Impressionist Rory Bremner may have inadvertently helped to defuse a Tory revolt against John Major, according to newly released official files.

Papers released by the National Archives show Bremner telephoned rebel MPs as an “experiment” to see if his impersonation of the prime minister could convince people who knew him.

But his appeal for support sounded so genuine the rebels agreed to “lay off” and help to carry the government through.

Bremner made the calls in October 1993 ahead of the launch of his new show on Channel 4 – just as Mr Major was preparing for a rough ride from Eurosceptics at the party conference in Blackpool.

The comedian rang MPs Sir Richard Body, John Carlisle and Ann Winterton, claiming to be the prime minister calling from Malaysia, where he was on an official visit.

When one of the MPs then contacted No 10, cabinet secretary Sir Robin Butler immediately tried to alert them that the calls were hoaxes.

However Sir Richard in particular was so taken in by Bremner’s impersonation he refused to accept he had not been speaking to Mr Major.

According to the official note of their conversation, he told Sir Robin it was “a very good thing” the prime minister had made the call.

He said he had spoken afterwards to Mr Carlisle and they had agreed they should back up Mr Major and help the government through.

Butler should tell the prime minister that the call had saved his bacon

“They had spoken to their ‘whips’ (Body indicated that he meant the unofficial whips of their group). They had taken the heat off the prime minister,” the note said.

“If John Major had made that call, he had done himself a good turn. Butler said that he had not made that call.

“Body replied: ‘Well you say that. But I can’t find any reason to criticise him for doing so. He had ‘rung around’ and they had ‘all agreed to lay off”.”

When Sir Robin told him Mr Major’s itinerary meant it was “physically impossible” for him to have made the calls, Sir Richard insisted he must have “slipped away” to do so.

“Body repeated that he did not think this was an impressionist,” the note said.

“Butler should tell the prime minister that the call had saved his bacon. ‘We sent word around to back him up at least until after the conference. He was obviously in a bad state. Now he is obviously regretting it. But I know his voice.'”

Mr Carlisle told Sir Robin he had been “half taken in” by the call until Sir Richard rang him to assure him it was genuine.

He said the caller had sounded agitated and asked whether he intended to stand against Mr Major for the party leadership.

He said the caller had added “Chris is here”, which he took to be a reference to Chris Moncrieff, the PA news agency’s political editor, with the inference that he could take the opportunity to put out a statement of support.

Sir Robin then contacted Channel 4 chief executive Michael Grade who told him that a letter was being sent to Sir Richard confirming the call was a hoax and assuring him it would not be broadcast without his permission.

He said no tape existed of the call to Mr Carlisle, while the call to Mrs Winterton had ended with her being told it was a hoax and she had refused to allow it to go out.

Mr Grade said he had given instructions that in future any hoax calls by Channel 4 purporting to be the prime minister would require his personal approval – which he would not grant if it touched on “political matters”.

“Michael Grade throughout was conciliatory and by implication apologetic, although I did not hear him issue the actual word ‘sorry’,” Sir Robin said.