THE Government’s controversial planning reforms will protect the "most precious environments" in the country, the Chancellor George Osborne insisted today.

But his comments on the new planning system, which will come into effect as soon as it is published next week, prompted renewed concerns that the majority of England’s countryside will be at risk from damaging development.

A bitter battle has raged over the plans to slim down more than 1,000 pages of planning guidance to just 50 since a draft version of the document was published last summer, amid fears it could lead to a return to urban sprawl.

Announcing that the final version of the national planning policy framework would be published on Tuesday, Mr Osborne said the central theme of the overhaul - a ``presumption in favour of sustainable development" - would stay.

Highlighting the pro-growth agenda which has driven the bid to reduce the planning framework, he said the move was the "biggest reduction in business red tape undertaken".

He warned: "Global businesses have diverted specific investments that would have created hundreds of jobs in some of the most deprived communities in Britain to countries like Germany and the Netherlands, because they couldn’t get planning permission here.

"That is unacceptable."

He said the new planning arrangements would come in with immediate effect, prompting concerns that local authorities which had not already drawn up "local plans" to steer development in their area would be forced to approve all schemes under a requirement to operate a default "yes" to development.

Adam Royle, spokesman for the Campaign to Protect Rural England, said Mr Osborne’s reference to protecting "the most precious environments" could spell bad news for the wider countryside.

"From the Chancellor’s words we fear the long-standing protection for the wider countryside will be abandoned.

"That would mean that 55% of English countryside, including many locally loved green spaces, could be placed at the mercy of developers.

"Also extremely worrying is the suggestion that communities may not be given any time to ensure their local plans conform to the new framework.

"This could leave more then one third of areas that don’t currently have a plan exposed to a crude ’presumption in favour of sustainable development’."

Friends of the Earth’s executive director Andy Atkins said: "Osborne says new planning rules will protect our most precious environments but unless they address the environmental challenges we all face, ministers will pave the way for a development free-for-all that will cost us all a fortune in the long run.

"Bringing in the changes will put local plans at risk and allow developers to ride roughshod over local communities."