Gordon Brown's relations with Health Secretary Johnson ‘at breaking point'

The allegation, which is circulating among senior Labour MPs, comes amid separate claims of a ‘blazing row’ between Mr Johnson and the Prime Minister.

Mr Brown has spent the past week planning an autumn relaunch of the Government, in the hope that a Cabinet reshuffle and an economic recovery plan will quell talk of a challenge to his leadership.

Gordon Brown and Alan Johnson: 'Close to breaking point'

But last night one Labour MP said that the party was ‘buzzing’ with talk that Mr Miliband had approached Mr Johnson shortly before the Foreign Secretary signalled his willingness to take on Mr Brown with a provocative article for The Guardian.

‘Miliband and Johnson met with one of Miliband’s aides,’ he said.

‘When they came out, the aide said, “We’ve asked him” – as in Johnson was asked to be Miliband’s deputy in a leadership run-off.’

A source in the Miliband camp, acknowledging the rumours, claimed that a meeting between the two men had been misconstrued.

‘They must have been spotted in a huddle at the national policy forum and people have put two and two together,’ the source said.

‘They have not discussed a leadership bid.’

The forum took place the day after Labour’s shock loss of the Glasgow East by-election, when party morale hit rock-bottom.

But suspicion in No10 over the intentions of Mr Johnson have been raised by his silence during the Prime Minister’s recent troubles.

In a Mail on Sunday survey of Cabinet support for the Prime Minister last week, Mr Johnson was one of six who did not respond to the question: ‘Should Mr Brown lead Labour into the next Election?’

A separate party source claimed that relations between Mr Brown and Mr Johnson had been strained ‘to breaking point’ by a ‘blazing row’ over the Embryology Bill.

The controversial legislation, covering stem cell research, was pulled from the Commons last month amid claims that Downing Street had been scared to alienate Catholic voters in Glasgow.

Labour MPs have also said they were approached by friends of Mr Johnson, 58, after the party’s defeat in the Crewe and Nantwich by-election, urging them not to ‘flush him out’ by talking up his leadership chances.

A Downing Street spokesman said: ‘The Prime Minister has made his support for the Embryology Bill very clear.’

Mr Johnson’s office failed to return calls.