The government-owned firm building HS2 has quietly withdrawn from a set of pledges to protect landscapes, wildlife habitats and residents along the route, The Telegraph can disclose.

HS2 Ltd has drawn up a new environmental policy, ditching explicit commitments to "avoid significant adverse impacts on health and quality and life" and "minimise" the effect of the scheme on the environment.

The new document also drops a previous pledge to fully restore agricultural land that is "disturbed" during construction.

The National Trust, the leading conservation charity, expressed alarm at "worrying signs" the firm was planning to renege on its earlier commitments, which were intended to allay concerns over the line's potentially harmful impact on the environment, and the noise levels that would be experienced by those living near the line.

Charities and MPs have warned that contractors have already begun causing irreversible damage to ancient woodlands as they clear the way for the line.

Ingrid Samuel, the National Trust's historic environment director, told The Sunday Telegraph that the new environmental policy was evidence that HS2 was "backtracking from its own commitment to deliver ‘an exemplar project’."