Angela Rayner's speech to a group of Labour activists on Tuesday night was arch, barbed, punchy and unflinching.

Delivered by the former deputy prime minister in a room at a Westminster pub, this was a 1,500 word scripted and rather devastating critique of Sir Keir Starmer's leadership, albeit without naming him.

The speech reads like a cry of frustration from a senior Labour figure who feels underwhelmed by what she sees as the party's underpowered performance in office.

It was not quite a manifesto, but was definitely an alternative vision for how Labour could govern and will reignite speculation that she is preparing to challenge Sir Keir for the top job.

Rayner was at her sharpest, certainly in terms of how Downing Street will see it, in four words in her conclusion.

Labour is, she claimed, "running out of time".

Quite the thing to say less than two years on from a landslide general election victory.

An impression has been left, she said, that the government "represented the establishment, not working people. At worst, we became it".

She added that "the very survival of the Labour Party is at stake – as a party and a movement we cannot hide, we cannot go through the motions in the face of decline. We are running out of time."

She also said "the Labour Party is at its best when we are bold," a line reminiscent of a restless Gordon Brown in 2003, appealing to what he called Labour's "soul" and arguing the party was "best when we are boldest."

And yes, Brown's ambitions were very clear back then.

Incidentally, when Labour folk appeal to their party to be more "bold" that is usually code for being more left wing.

Rayner was addressing the relatively new Mainstream group within the Labour Party, often associated with the Greater Manchester mayor Andy Burnham.

The group says it wants "a popular Left with heart and vision" – a mission statement that in itself reads like an implicit criticism of the current government.

Some on the right of the party say Mainstream is too willing to flirt with the hard left, including some who were associated with former Labour leader Jeremy Corbyn.

One MP told the BBC: "A faction launched calling for the end of factionalism. Can't make it up."

Wrapped up in Rayner's wider critique was a broadside at a central plank of current government policy - Home Secretary Shabana Mahmood's migration plans.

Some Labour MPs have privately expressed surprise that Rayner had chosen to set herself against the government's planned restrictions on indefinite leave to remain, which gives a person the right to live, work and study in the UK for as long as they like and apply for benefits if they are eligible.

One argued that it is "easy to be soft and cuddly" but "the huge numbers that came in under Boris [Johnson]" getting indefinite leave to remain would fuel support for Reform UK.

Another Labour MP said the reason Rayner was opposing the policy was simple, claiming that "the whole PLP hate it," a reference to the Parliamentary Labour Party.

A minister said that Rayner's support in a potential leadership campaign was not as assured as many believed, suggesting that her decision to attack the government from the left on immigration was designed to "firm up" support from "soft left" MPs.

While Rayner's opposition is incendiary, the changes to indefinite leave to remain do not require a parliamentary vote so there is no obvious moment for the opposition to come to a head.

And crucially, when it comes a possible leadership bid, Rayner's tax affairs are understood to remain unsettled.

Several Labour MPs this morning questioned whether she could stand for the leadership with the issue outstanding.

They said that the tax problems which precipitated her departure from the cabinet last autumn are occasionally mentioned by voters on the doorstep as an example of their frustration with the Labour government.

It is notable that Rayner's intervention has come after a few weeks where the leadership issue appeared to have calmed, not least because of the prime minister's handling of the war in Iran, for which he has mostly won credit within the parliamentary Labour Party.

"The fragile peace in the team room is shattered," one MP said.

Invited to comment on Rayner's remarks to Tuesday night's gathering, Downing Street politely declined.

With Prime Minister's Questions a few hours away, those invitations to comment may only just be beginning.

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