A genetic test to tell a true Scottish wildcat from a hybrid could be ready as early as Christmas, scientists have revealed.

Dr Paul O'Donoghue of Chester University, who is developing the test in partnership with the Royal Zoological Society of Scotland WildGenes Lab in Edinburgh, described the work so far as "incredibly encouraging".

He said: "Initial results suggest a diagnostic wildcat test will be available."

Many Scottish wildcats have bred in the wild with domestic cats to produce hybrids, so it is not known how many pure-bred wildcats remain, with the official estimate of about 400 regarded as too optimistic.

Conservationists warn that if interbreeding continues, the species could be wiped out in five years. The genetic test should allow the true remaining wildcats to be identified and steps taken to protect them.

Douglas Richardson, of the Highland Wildlife Park, said: "We have this iconic emblem of the Highlands, and if we don't get our finger out it will become extinct, guaranteed."

Conservationists such as Steve Piper of the Scottish Wildcat Association are pressing the Scottish Government and Scottish Natural Heritage (SNH) to move quickly so that action can be taken as soon as the test is ready, but are frustrated by what they regard as a lack of progress so far.

If enough true wildcats were discovered to breed from, Mr Piper would favour the creation of a "mainland island" for the cats on a peninsula like Ardnamurchan. A spokesman for SNH said efforts to protect the wildcat had to be made in a co-ordinated fashion.