PRESS RELEASE

Transport Action Network (TAN) are appalled at the news¹ that National Highways are seeking to remove measures to reduce and monitor the air pollution impact of the Lower Thames Crossing project on Epping Forest.

When National Highways applied for planning permission (a Development Consent Order or DCO) for the Lower Thames Crossing (LTC) they promised to implement measures to reduce air pollution impacts and to monitor the increased pollution due to extra traffic caused by LTC. These measures included temporarily reducing the speed limit from 70mph to 60mph on the westbound carriageway of the M25 between junctions 26 and 27 to mitigate air pollution. Monitoring of nitrogen and other air pollutants in this area for four years was also promised.

The purpose of the speed reduction and monitoring was to mitigate the impact on highly protected ancient woodland at Epping Forest Special Area of Conservation (SAC) which would be harmed by the nitrogen and other pollutants from extra traffic caused by the LTC. The Transport Secretary only granted the DCO as she “concluded that taking into account the mitigation measures it is permissible for her to give consent for the Proposed Development.”²

However, in a consultation launched on 30 June 2026, National Highways are proposing to remove the M25 speed reduction requirement and air pollution monitoring and instead buy nearby agricultural land and create “enhanced habitats” near the M25 and Epping Forest SAC.

If the proposal goes ahead, it would elevate air and noise pollution on the M25, and cause harm to the ancient woodland at Epping Forest. Planting trees on nearby agricultural land would not prevent the harm to Epping Forest.

Just last year National Highways applied to establish the air pollution monitoring baseline after construction work had started, which Transport Action Network strongly objected to³ but was allowed by the Transport Secretary. Now National Highways is attempting to remove the requirement to monitor altogether.

Abby Coften, Chief Executive, of TAN, said:

“National Highways is yet again trying to wriggle their way out of their environmental commitments. It is completely unacceptable to make promises in order to get planning permission, only to break those commitments later. The promises to reduce speeds and air pollution and undertake monitoring were made for good reasons, to protect the ancient woodland at Epping Forest. Planting saplings won’t stop that pollution from happening.

“They are also proposing to completely remove air quality monitoring so there is no way to measure the impact or evidence of their claims. It’s just further confirmation of their greenwashing of the scheme.”

TAN are calling on their supporters to object to the National Highways consultation which ends on 28th July here: Material Change Consultation – National Highways.

ENDS

Notes for editors

1. National Highways launched a consultation on 30 June 2026, which will end on 28 July. For more information see: https://nationalhighways.citizenspace.com/ltc/material-change-consultation/ ↩︎
2. Decision Letter for Lower Thames Crossing Development Consent Order, para 596, March 2025 ↩︎
3. TAN’s response to the consultation on the application for a Non Material Change to the LTC’s DCO, October 2025 ↩︎