More than 200 ancient woodlands are currently under threat from development, and many more could be at risk without changes to the proposed planning reforms, campaigners are warning.

The Woodland Trust said 630 ancient woods had been threatened by development such as quarries and roads in the past decade, with 111 sites lost in 10 years due to weaknesses in planning policy, and 225 still under threat.

New maps from the trust show dozens of woodlands dating back more than 400 years at risk around London, with others threatened from Cornwall to northern England.

The final version of a major overhaul of the planning rules, which the government insists is needed to boost economic growth but has also provoked fears among campaigners of inappropriate development and urban sprawl, is expected shortly.

Before its publication, the Woodland Trust issued a last-ditch plea to ministers to close what they say is a loophole in the proposed planning framework, which focuses on "sustainable development", to prevent more ancient woods being at risk.

The trust fears provisions in the new document, which says planning permission should be refused if it leads to the loss or deterioration of irreplaceable habitats such as ancient woodland or aged trees, are undermined by the caveat: "unless the need for, and benefits of, the development in that location clearly outweigh the loss".

Against a backdrop of a presumption in favour of development running through the reforms, this could lead to more woodland being lost to development, the campaigners warn.

With just 15% of England's ancient woodlands covered by protections such as being designated sites of special scientific interest and only 2.7% of the country covered in ancient woods, the trust said any further loss of woodland would be too much.

It said its call for greater protection of woodlands was backed by a majority of MPs, with a recent poll for the charity of 150 MPs revealing that four-fifths (81%) supported such a move.

Sue Holden, chief executive of the Woodland Trust, said: "The statement given by the prime minister's spokesman this week, in which he said a relentless focus on growth must be at the forefront of any forthcoming policy decisions, is cause for concern if the environment is not given equal consideration.

"Ancient woodland is rare, irreplaceable and home to more wildlife of conservation concern than any other land habitat.

"As 81% of MPs support the call to ensure greater protection for ancient woodland, in a free vote this would guarantee removal of the loophole which is critical to ensure ancient woodland is afforded the protection it needs to survive from development pressure.

"Covering just 2.7% of England's land area, each hectare of ancient woodland lost at this point is one hectare too many. No form of mitigation will compensate for its loss."

Ancient woodlands are areas that have been wooded continuously since 1600, often forming the UK's richest land habitat, which is home to a wide array of wildlife including more than 230 rare or threatened species.

A spokesman for the Department for Communities and Local Government said: "The government has repeatedly made clear that it is committed to safeguarding the natural environment and ensuring strong protections for ancient woodland, the green belt, areas of outstanding natural beauty and many other countryside treasures.

"The draft framework retains the same protections already in place and makes clear that planning permission should be refused for a development that would result in the loss of ancient woodland or veteran trees."