A consequence of Part 3 is that decision-makers are to disregard the environmental impact of development for the purposes of Part 6 of the Conservation of Habitats and Species Regulations 2017 where Environmental Delivery Plans are put in place and the developer pays the relevant nature restoration levy (amended sch. 4 (1)). The Bill as introduced was discussed in a blog post by Esther Drabkin-Reiter and Michael Feeney (see here).

Part 3 of the Bill received significant criticism from, inter alia, the Office for Environmental Protection (“OEP”) on the basis that there were “fewer protections for nature written into the bill than there are under […] existing law” (see, the OEP Letter and Advice to Government).

Over the summer, the Government appears to have taken on board some of the criticisms and has made a number of amendments to the Bill as it entered the Lords Committee stage. This blog post reviews some of the key changes to Part 3 of the Bill.

Note: references to ‘old’ clauses are to the Bill as introduced, and references to the ‘amended’ clauses are to the Bill as amended by the Government prior to the Lords Committee debate (17 September 2025).

The “overall improvement test”

Part 3 of the Bill aims to introduce new Environmental Delivery Plans (“EDPs”). These are to be prepared by Natural England, and made by the Secretary of State. In brief, these plans are to set out (amended cl. 53):

The environmental features that are likely to be negatively affected by the development to which it applies,

The conservation measures that Natural England are to take to protect those environmental features,

The amount of the nature restoration levy payable to developers by Natural England to cover the cost of those conservation measures, and

The environmental obligations in relation to development that are discharged, disapplied or otherwise modified if the developer pays the nature restoration levy.

The Secretary of State may only make the EDP, if the Secretary of State “considers that the EDP passes the overall improvement test” (amended cl. 59(3)).

In the Bill as introduced this test was met if “the conservation measures are likely to be sufficient to outweigh the negative effect, caused by the environmental impact of development, on the conservation status of each identified environmental feature” (old cl. 55(4)).

This test had been widely criticised for not providing sufficient certainty that the EDP would actually ensure the environment was not adversely affected by new development to which an EDP applied.

Under the amended Bill, an EDP will pass the overall improvement test if “by the EDP end date, the effect of the conservation measures will materially outweigh the negative effect of the EDP development on the conservation status of each identified environmental feature” (amended cl. 59(4)).

The amended clause has certainly strengthened the “overall improvement test” when compared to the original version of the Bill. It does this in two ways.

First, rather than considering if the effect of the conservation measures is “likely” to outweigh negative effects, the Secretary of State must consider whether the conservation measures “will” outweigh the negative effect. This change in language requires a greater degree of certainty on the part of the Secretary of State as to the effect of the conservation measures.

Second, under the amended Bill, the Secretary of State must consider the conservation measures to “materially outweigh” the negative effect of EDP development, rather than just “outweigh”. The addition of the term “materially” tilts the balance and indicates an EDP should not be made by the Secretary of State where there is an uncertainty as to the effectiveness of the conservation measures.

Although the amended Bill has strengthened the “overall improvement test”, it is arguable that it still does not provide the same levels of protection as current law. The new test is framed as a balancing exercise. Such a weighing exercise inevitably incorporates greater degree of judgement and subjective evaluation than the test under reg. 63(5) Conservation of Habitats and Species Regulations 2017 which specifies the relevant decision-maker can only agree to the plan or project after having ascertained that it “will not” adversely affect the relevant environment. An assessment to determine this “cannot have lacunae and must contain complete, precise and definitive findings and conclusions capable of removing all reasonable scientific doubt as to the effects of the works proposed on the protected site concerned” (Sweetman v An Bord Pleanála (C-258/11) [2014] PTSR 1092, para. 44).

Moreover, the “overall improvement test” requires balancing over the lifetime of the EDPs when the exact development and environmental harms are unknown. In contrast, the assessment under reg. 63 of the Conservation of Habitats and Species Regulations 2017 is focused on a single plan or project. Arguably, this allows for a more precise assessment of the environmental harms.

Whether EDPs will actually lessen environmental protection is, of course, uncertain. It must be recognised that EDPs, when compared to the current framework, will allow for greater strategic planning of environmental conservation. Such strategic planning may allow Natural England to implement more significant programmes of measures which are longer-term than what can currently be achieved under the Conservation of Habitats and Species Regulations 2017.

Compensation measures

A key criticism of the Bill, as introduced, was that it appeared to allow for a greater use of compensation measures when compared to the Conservation of Habitats and Species Regulations 2017.

At present, compensation measures are a measure of ‘last resort’. They can only be used where it is not possible to avoid or mitigate harm from development. Even then, such measures are only available where there is an “imperative reason of overriding public interest” (reg. 64, Conservation of Habitats and Species Regulations 2017).

Under the Bill, as introduced, EDPs were to set out “conservation measures” that

• Addressed the environmental impact of development on the identified environmental features, and
• Contributed to an overall improvement in the conservation status of the identified environmental features.

Clause 50(4) of the Bill, as introduced, allowed Natural England to set out conservation measures that did not directly address the environmental impact of development on that feature at that site but instead seek to improve the conservation status of the same feature elsewhere. In other words, compensation measures.

This clause was criticised on two bases. First, as indicated above, it removed the so-called ‘hierarchy’ between avoid, mitigate and compensate. Second, the OEP expressed concern that the drafting could “allow a protected site to be harmed in such a way as to affect its integrity, even in an extreme case to be destroyed entirely, in reliance on compensatory measures to be implemented elsewhere” (see, the OEP Letter and Advice to Government, p. 5).

The amended Bill has sought to address these criticisms. Thus, amended clauses 55(5) and 55(6) provide:

(5) Where an identified environmental feature is a protected feature of a protected 10 site, the EDP may set out conservation measures that do not directly address the environmental impact of development on that feature at that site but instead seek to improve the conservation status of the same feature elsewhere.

(6) But an EDP may include conservation measures of the type mentioned in subsection (5) only if Natural England considers that such measures would make a greater contribution to the improvement of the conservation status of the feature than measures that address the environmental impact of development on the feature at the protected site itself.

These clauses re-introduce a degree of hierarchy, as compensation measures are only to be introduced if they have a “greater contribution to the improvement of conservation status” than mitigation measures. Moreover, the comparative element to clause 55(6) arguably eliminates the concern that the integrity of the site could somehow be harmed or destroyed as Natural England would be required to compare this position to one where mitigation measures were used. It is unlikely that harm to the integrity of a site would provide a greater contribution to the improvement of conservation status than mitigation measures.

Nevertheless, it is doubtful that the amended Bill will silence all critics. The revised clause 55(6) has not re-introduced the requirement that there be “imperative reasons of overriding public interest” before compensation measures are used. Such a hurdle had been difficult to overcome in many cases and limited the availability of such measures. As such, it is likely the revised clause will result in the greater use of compensation measures. Those who believe that we cannot truly compensate for environmental harm will be disappointed at this. However, affording greater flexibility into the system is a stated aim of these changes to the Bill. In its summary of the changes to the Bill, the Government has stated, “it is crucial to embed flexibility in this new approach to avoid the sub-optimal outcomes that occur under the current system’s rigid approach to the selection of environmental interventions” (see here).

Other key changes

There are a number of other changes that have been made to the Bill. Below is not a comprehensive list, but a number of notable amendments.

First, under amended clause 88(1)-(2), both Natural England and the Secretary of State must now take account of the best available scientific evidence in exercising any functions in relation to the preparation, amendment or revocation of an EDP. There was no such requirement in the Bill as introduced.

Second, EDPs must now set out the “anticipated sequencing of the implementation of the conservation measures by reference to the development to which the EDP applies” (amended cl. 55(4)). The Government’s summary of the changes to Part 3 of the Planning and Infrastructure Bill argues that this change will “provide additional assurance that EDPs will not lead to open-ended or irreversible impacts from development. This would include detail as to whether and which conservation measures must be in place in advance of development coming forward, ensuring that no irreversible harm could occur to an environmental feature.”

At present, there is no requirement in legislation that the sequencing include the details summarised by the Government in its summary of changes. As Esther Drabkin-Reiter and Michael Feeney noted in their blog post on the Bill as introduced, the effectiveness of this clause (and many others in the Bill) is likely to depend on the fleshing out of the Bill in secondary legislation and guidance.

Third, EDPs must now include back-up measures. In the Bill as introduced, such measures were discretionary (old cl. 50(5)). Amended clause 55(7) provides, “An EDP must include conservation measures that are not, at the time the EDP is made, expected to be needed but which must be implemented in the circumstances set out in the EDP.”

Of course, there may be more changes to come as the Bill continues to progress through Parliament (the House of Lords Report Stage commences on 20 October 2025). It is noteworthy, however, that in the latest round of changes, published on 13 October 2025, the Government did not take the opportunity to make any substantial alterations to Part 3 of the Bill. This may reflect how the changes to the Bill, outlined above, have subdued those critical of the changes proposed in March 2025 when the Bill was introduced.  

Emma Rowland is a barrister at Francis Taylor Building specialising in environmental, public and planning law.