The Royal College of Physicians (RCP) has been accused of attempting to skew the results of a poll of its members' views on assisted dying, with a former official threatening legal action over a vote he calls a 'sham'.

The college plans to poll its members over whether they support helping patients end their lives, and has said unless there is a 60 per cent majority for or against assisted dying it will adopt a position of neutrality on the issue. At present it opposes it.

However, two dozen doctors and academics have written to the Times objecting to the terms of the poll, which they say amounts to 'tacit support for assisted suicide'.

The signatories, who include Nigel Biggar, regius professor of moral and pastoral theology at Oxford, say: 'We are worried that this move represents a deliberate attempt by a minority on [the college's governing council] to drop the college's opposition to assisted suicide even if the majority of the membership vote to maintain it.' They urge a return to a 'more orthodox, justifiable and democratic approach'.

Currently, helping someone to commit suicide is punishable by up to 14 years in prison. A RCP vote in 2014 saw 58 per cent of doctors opposed to a change in the law, with 44 per cent saying the college should be formally opposed. Thirty-one per cent said it should be neutral and 25 per cent wanted it to support assisted dying.

John Saunders, a former chairman of the college's ethics committee, has threatened a judicial review of the poll, saying it is 'manifestly unreasonable' that if it delivers the same result as a 2014 vote it will change the position.

He said the college had 'come under a disproportionate influence by advocates of physician-assisted suicide'.

RCP president Andrew Goddard told the Times: 'Because doctors are divided, the RCP wants to ensure that we only hold a position one way or another if there is a clear majority . . . The RCP has not campaigned on this issue and has no plans to do so.'

A spokesman for Christian social advocacy charity CARE, James Mildred, said: 'What this letter published today very clearly demonstrates is how strongly some doctors feel about the way in which the Royal College of Physicians has framed this new poll on assisted suicide.

'The poll has been designed to effectively guarantee the College can go neutral on this controversial and sensitive issue, by requiring a supra-majority of 60 per cent just to maintain the status quo of long-standing opposition to assisted suicide.'

Neutrality, he said, would 'send a signal that the College, made up of 35,000 members and fellows, is no longer opposed to doctors prescribing lethal drugs to enable patients to end their own lives. This is tacit support for assisted suicide.'

He said: 'We think that there is no way an assisted suicide law can ever be made safe from abuse or exploitation. Opening the door to assisted suicide would be a dangerous move which would put pressure on elderly and vulnerable people.

'It would be better for the College to withdraw this current survey and, if it so wishes, start again but make sure it's construed in a more fair and balanced way.'