Scope for challenge to NSIP’s to be limited further under UK Government proposals

Beautiful night an Sunset view of Big Ben and the Houses of Parliament in London, illuminated over the River Thames with city lights reflecting on the water. UK

The UK Government has published a policy paper outlining its intention to add two optional mechanisms to the Nationally Significant Infrastructure Projects (NSIP) consenting mechanism.

26.05.2026

Optional mechanisms to the NSIP consenting mechanism

1. Parliamentary Authorisation Mechanism (energy projects only): 

For energy projects, the consent process would be amended as follows:

  • Stage 1: Energy Secretary determines if the project is of “Critical National Importance.”
  • Stage 2: House of Commons votes to approve or reject this designation.
  • Stage 3: DCO submission and examination process continues as normal
  • Stage 4: DCO decision is subject to vote in House of Commons.

If approved at Stage 4, the DCO will have a special statutory status akin to an Act of Parliament and cannot be challenged by judicial review (other than human rights grounds)

2. Challenge Window Mechanism (all NSIPs)

This has the following stages:

  • Stage 1: Draft decision is published by Secretary of State. This triggers a fixed period during which any judicial reviews must be lodged.
  • Stage 2: Secretary of State considers and addresses any issues arising from JR claims.
  • Stage 3: Secretary of State issues final DCO

This mechanism limits the scope of challenge significantly. 

If a claimant brings a claim after the final DCO is issued on the same grounds to those the Secretary of State is deemed to have considered, the Courts will be on stronger footing to refuse permission or relief.

If a claimant brings a claim on grounds that haven’t been raised during the consent process or challenge window, the Courts will be expected to refuse permission (following proposed amendments to the law).

Curiously, the challenge window mechanism could actually increase the number of challenges we see or at least the grounds raised within such challenges. Those filing claims will be aware that the Secretary of State will need to consider their concerns and may feel there is a much higher chance of having these reflected in the amended draft (and therefore more worth the time and cost of putting in a challenge) than in the normal JR process. 

Why is this considered necessary?

To proceed with such reforms, the Government will need to anchor its proposals in a legitimate public interest. Their view is that the increasingly unstable geopolitical sphere merits further action to quickly deliver infrastructure and secure a transition to clean power.

These changes are intended to deliver a high degree of certainty against delay in cases where there is a clear national interest in attaining the UK’s energy security and net zero objectives.

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