A NEW government report has said more work needs to be done by HS2 Ltd to protect the environment.

The Environmental Audit Committee report, which was released yesterday, concluded the company behind the controversial high speed railway line should aim higher than simply trying to mitigate the worst impacts on wildlife.

The report said HS2 needed to carry out further environmental surveys as up to 40 per cent of land the planned route will run through still hadn't been examined by rail chiefs.

MPs are set to discuss the scheme in the House of Commons later this month, despite claims they have not been provided with enough information ahead of the debate.

National planning guidelines state that "if significant harm to biodiversity resulting from a development proposal cannot be avoided, adequately mitigated, or, as a last resort, compensated for, then planning permission should be refused".

And the report said: "[HS2 Ltd] has significant work to do to demonstrate that it has put the 'mitigation hierarchy' at the heart of its approach, given the environmental damage expected to ancient woodlands, Sites of Special Scientific Interest and local wildlife sites.

"Where such biodiversity loss is genuinely unavoidable and cannot be mitigated, compensation measures should be applied to the fullest extent possible."

In an Environmental Audit Committee hearing before the report was compiled, members of the Campaign to Protect Rural England said: "The Environmental Statement seems to be about trying to minimise environmental harm rather than seek any environmental opportunities. There is a massive lost opportunity there...HS2 should be part of a bigger strategy to try to maximise use of brownfield land and reduce land-take by car parking and roads, but unfortunately it is not being planned in a joined-up fashion."

The campaign group also said HS2 Ltd had "failed to disclose information on why potential alternative [routes] had been dismissed".

It had also been claimed reducing the speed of trains from 360kph to 300kph along a route with more curves would significantly reduce carbon emissions and result in a loss of fewer 'environmentally sensitive features' such as areas of ancient woodland.

But research group Greenguage 21 said this would require more construction work - and although slower trains would result in a 19 per cent reduction in energy consumption, it would only lead to a seven per cent overall reduction in carbon emissions.