THE Government is to be asked to review its control strategy on a deadly disease threatening to decimate the UK's ash trees following new evidence from a West Somerset plantation.

Ash trees at the National Trust's Holnicote Estate have survived 'ash dieback' - Chalara fraxinea - for far longer than previously thought possible.

Only ten per cent of the estate's 6,000-strong population of ash planted in 2001 to mark the Millennium are showing any signs of the disease, despite having been infected for five years longer than any other tree in the UK so far.

The disease is also present in one other small plantation nearby but does not appear to have spread further, which is at odds with Government predictions which suggest it should have spread and infected more trees in this time.

And experts believe the evidence suggests there may be potential to slow the spread of ash dieback in the British countryside.

They say the findings suggest tackling the disease in the UK may not be a lost cause and control measures could slow its spread from South East England where it appears to have been blown from mainland Europe.

Dr Simon Pryor, the trust's natural environment director, said even the trees affected on the Holnicote plantation had not suffered as much as expected and very few had died, despite apparently having had the disease for nearly a decade.

"Whilst we don't want to be too optimistic on the basis of this one outbreak, this does confirm the view we've held from the outset that it is worthwhile removing affected trees in order to try and slow the spread, especially in places like this so far from the main area of the disease in the South East," he said.

"We will be asking the Government to look again at its control strategy in the light of this new evidence, which to us does not appear to fit with current modelling."

The outbreak of ash dieback at Holnicote was only discovered in September during routine inspections for the disease.

It is thought the trees, like thousands of others imported to the UK in the early 2000s, were infected whilst being grown in central Europe.

Holnicote countryside operations manager Mark Courtiour, said discovering the disease at such a large site had been particularly heartbreaking.

"Like others we were shocked to discover that the trees we thought were being grown in British nurseries were actually being grown on and imported from the continent," he said.

"We will be felling all the infected trees as a matter of priority and filling the gaps with other species.

"However, there is a real glimmer of hope and we are continuing inspections at the site."

Ash makes up a third of the UK's entire tree population, meaning the British landscape could be radically changed if ash dieback is allowed to spread.