"Scandalous" plans to speed up the Northern Line by building a crucial' control centre next to the ancient Highgate Woods must be urgently reconsidered for the sake of the environment, it was claimed this week.

Tube Lines, which is responsible for maintenance and upgrades on the Northern Line, has been accused of being uncompromising' and failing in its duty to the environment, after it revealed plans to build a controversial warehouse-like structure' closer to the sensitive woodland site than originally planned.

The Corporation of London (CoL), which runs the woods visited by millions each year, has released a joint statement with the Highgate Society, Liberal Democrat councillors and new Hornsey and Wood Green MP Lynne Featherstone, calling for improvements to reduce the visual and ecological impact of the centre. They say that, despite promises from Tube Lines, nothing much has altered.

Catherine McGuinness, chairman of the CoL's Highgate Wood management committee, has written to Tube Lines boss Terry Morgan, urging him to reconsider the plans and to express her disappointment and concern' that the company is backtracking on promised changes to the planned building.

Tube Lines, which has started laying foundations for the centre near Archway Road and Lanchester Road, does not need planning approval but says it has gone to lengths to engage with residents, councillors and the CoL and accommodate their suggestions such as a green roof and screening.

Highgate Wood headkeeper Ray Poole has previously raised concern over the disruption the building would cause to rare breeds of bats which use a secluded spot near the site as a breeding roost.

Highgate ward councillor Bob Hare said: "It's a scandal. They have given us absolutely nothing to protect the woods and have failed in their duty to the environment. We have been promised various things but they are just stringing us along."

Mr Morgan responded this week by saying: "We have sought to balance the interests of Northern Line users throughout the capital with the needs of the local community at Highgate and I believe that we have managed to reach a reasonable compromise solution.

"We have been open-minded and flexible to the suggestions presented to us."

A spokeswoman for Tube Lines, which wants to finish building by September 2006 in order to meet London Underground targets, added: "We have not ruled anything out. We have started with the building but can still discuss various finishes later."