Mr Allason, a 41-year-old spy writer who has represented Torbay since 1987, was the only Tory MP who failed last week to vote for the Government in a vote of confidence.
Parliamentary whips and constituency association officials yesterday said the party could not afford to lose another MP. Mr Allason has been told to report to Richard Ryder, the Government chief whip, before the Commons rises tomorrow for the summer recess.
Torbay, where Mr Allason won a reduced majority of 5,787 at the 1992 general election, is high on the target list of seats for the Liberal Democrats.
Party activists in the Devon constituency, who meet tomorrow, said Mr Allason could respond to deselection moves by resigning his seat and forcing a by-election.
'Allason has been consistently anti-EC, and he won't lose much support for that. If anything the tourist and fishing industries don't think he's gone far enough,' a local party official said. 'We've been given the nod . . . to let the whips sort him out.'