A key ally of Wes Streeting today demanded the ex-health secretary be involved in talks with Keir Starmer and Andy Burnham over resolving Labour’s leadership chaos.

Jess Phillips, a former Home Office minister, called on the three men to ‘act like grown-ups’ amid the party’s civil war over who should be prime minister.

Sir Keir has repeatedly vowed to fight any challenge to his leadership and insisted he will not ‘walk away’ from Downing Street.

But Mr Burnham’s thumping win in the Makerfield by-election has unleashed a fresh wave of demands for the embattled Prime Minister to quit No10.

The number of Labour MPs calling for Sir Keir to resign has now topped 100, while party grandees – including Cabinet ministers – have told Sir Keir that his time is up.

Many within Labour want Sir Keir to agree to a timetable for handing over power to Mr Burnham without a leadership contest, in a coronation for the former Greater Manchester mayor.

But Ms Phillips insisted Mr Streeting should also be part of any discussions and to be given the chance to put his case for being leader to Labour MPs.

This is despite suggestions Mr Streeting – who has claimed to have the required backing of 81 Labour MPs to trigger a leadership contest – might be prepared to stand aside in favour of Mr Burnham in return for a top Cabinet role.

A key ally of Wes Streeting (pictured) has demanded the ex-health secretary be involved in talks with Keir Starmer and Andy Burnham over resolving Labour’s leadership chaos

Jess Phillips, a former Home Office minister, called on the three men to ‘act like grown-ups’ amid the party’s civil war over who should be prime minister

Ms Phillips quit as safeguarding minister in the wake of Labour’s local elections meltdown last month with a scathing resignation letter accusing Sir Keir of failing to be ‘bold’.

Speaking to BBC Radio 4’s Today programme on Saturday, Ms Phillips said she couldn’t ‘sit by’ and allow ‘unpopular’ Sir Keir lead Labour to defeat against Reform UK at the next general election.

‘I can only speak from what I know personally, from knocking doors all over the country… is that Keir Starmer is really, really deeply unpopular on the doorstep, not just in polling,’ she said.

‘I can’t sit by and just watch that decline deliver Nigel Farage to No10.’

She added: ‘We have to be grown up about this. We have to say, do we want to continue to manage decline in our popularity, or do we need to do something about it?’

Ms Phillips called for Labour MPs to insist on a leadership contest between rival candidates – rather than a coronation for Sir Keir’s successor – after Mr Burnham arrives in Parliament to be sworn in as Makerfield’s new MP on Monday.

‘If you want to be the leader of our country, as well as the leader of the Labour Party, you should be tested with the rigour of at least some manner of contest,’ she said.

But Ms Phillips suggested the choice of leader could be settled among Labour MPs – rather than the party’s wider membership – as she cautioned against a ‘protracted’ contest.

‘Lots of people don’t know Andy Burnham, have never worked alongside him, and that’s not his fault,’ she added.

‘It would be much better if this wasn’t protracted and didn’t go on for a long time.

‘So I look forward to Andy Burnham arriving on Monday, and those who are prospective candidates setting out their stall.’

Asked if Mr Streeting had a viable chance of winning a leadership contest, Ms Phillips replied: ‘He has support in the Parliamentary Labour Party (PLP). I speak to these people every day… I am literally around all of these people every day.

‘Both of them [Mr Streeting and Mr Burnham] have to get in front of… each other, and act like grown-ups. And, frankly, I think Keir Starmer should be in that room.’

Ms Phillips backed Labour peer Harriet Harman’s proposal for only Labour MPs – rather than party members – to choose between Sir Keir, Mr Burnham or Mr Streeting as leader.

This is despite Ms Phillips admitting, ‘as a feminist’, that she was uncomfortable with the prospect of ‘three blokes in a room deciding on the future of the country, and the party’.

Meanwhile, it has been suggested that Mr Streeting could allow Mr Burnham’s coronation as Sir Keir’s successor if he is offered a senior job in Mr Burnham’s new administration, possibly as Chancellor.

‘The choice will be: bring Wes in and give him a big job – or else face the scenario no one wants, which is a contest,’ one MP told The Times.