MILITARY training on Dartmoor came under fire from the Open Spaces Society this week.

The group has written to the Defence Estates calling for any plans for increased investment in the Dartmoor training area to be dropped.

But the Army argues that its presence helps to protect the land from dorestation and intensive agriculture.

General secretary of the Open Spaces Society Kate Ashbrook said on Tuesday that the military should be reducing its activity on the moor and should not consider making a national park a core training site.

'It is clear that military training and national parks are incompatible and that this conflict can never be resolved,' she said.

The society says that as part of its strategy for the Defence Estate, the Ministry of Defence will select its core training sites by next year. The core sites will be the focus of future use and investment.

Ms Ashbrook said the group believed the Ministry of Defence was not taking any account of whether training land was in a national park.

'The national parks in England and Wales are our top landscapes, designated for their outstanding natural beauty, and as places for quiet recreation.

'So there is a danger that the military training area on Dartmoor and in other national parks could become core sites just when the military should be reducing its activity there, not expanding it,' she said.

The society argues that serious damage is done to parts of Dartmoor by military exercises, claiming they destroy the wilderness, cause excessive noise, and pose a risk to the public from unexploded missiles.

The society says Dartmoor's unique prehistoric archaeology is under threat from battering by live fire.

The Army say that on Dartmoor, they administer some 30,000 acres of which 3,400 are MOD freehold, for use by a number of units, including the Royal Marines. 'It is not true to claim there are plans to "expand" its use there,' said an Army statement.

The Army say just 30 per cent of their training land is located in national parks, representing less than five per cent of the total area designated as national park land.

The Army statement said that Ministry of Defence training areas were the 'jewel in the environmental crown' as they protected the land from forestation and intensive agriculture and refrained from the use of herbicides and pesticides.

The Army say they follow a number of restrictions to their live firing and 'dry' training exercises on Dartmoor, principally a cessation during August and on all Sundays and Bank Holidays.

The Army Training Estate said: 'Work to identify core training sites is still at a very early stage and it is too soon to guess completion'.

The estate say the military has had a presence on Dartmoor for 200 years, pre-dating the moor's designation as a national park.

The Open Spaces Society says it plans to lobby the Duchy of Cornwall and Dartmoor National Park Authority not to renew the licences for military training on the moor when they expire in 2012.