Angela Rayner is embroiled in an escalating row with Unite over her role in the long-running bin strikes in Birmingham.

The union announced earlier it had suspended the membership of the deputy prime minister, who has been urging striking bin workers to accept a deal to end the dispute tabled by the Labour-run city council.

But a Labour source said she had already quit the union and “won’t be pushed around,” branding the announcement a “silly stunt”.

The union, which says it followed a motion approved by delegates at its policy conference, has insisted Rayner is on its membership system.

The motion also threatened to rethink its relationship with Labour if any of its members are made redundant.

In any event, by making its announcement Unite has decided to advertise a very public political rift with the deputy prime minister.

Unite is affiliated to Labour, giving it seats on the party’s ruling national executive committee and delegates to its annual conference.

It did not donate to the party’s election campaign last year, but made donations worth £10,000 towards Rayner’s campaign, according to her register of interests.

Labour is less dependent on union financial backing than it was under Jeremy Corbyn, with the party having widened its sources of funding under Sir Keir Starmer.

But if the union chose to disaffiliate, it would still deliver a significant financial blow.

Unite is also its biggest union funder through the affiliation fees that members pay to the party, currently £1.2m a year.

Senior union sources say the bin strike is the tip of the iceberg of discontent.

What may really sink the union’s relationship with the government is a range of other issues, such as the attempted welfare cuts, fears for jobs in the oil and gas sector, and a workers’ rights agenda they do not believe goes far enough.

Members of Unite walked out in January over plans to downgrade some roles as part of the city council’s attempts to sort out its equal pay liabilities.

The dispute initially centred on the council’s decision to remove waste recycling and collection officer (WRCO) roles – which the union said would leave about 170 affected workers up to £8,000 a year worse off.

The council has disputed this, saying the maximum loss would be just over £6,000 and would only affect 17 workers, with pay protected for six months.

The authority also says the role could not be reinstated without opening it up to a potential equal pay liability.

Unite has also urged the council to guarantee long-term pay for Grade 4 bin lorry drivers, claiming in April that bin lorry drivers’ pay could fall from £40,000 to £32,000 under new council plans.

An all-out indefinite strike was announced in March, and a deal to end industrial action has not yet been reached.

Conciliation service Acas has been mediating in the negotiations since May, but talks broke down on Wednesday, with council leader John Cotton saying the authority had “reached the absolute limit of what we can offer”.

The union has also previously blamed government-appointed commissioners, who have been overseeing the council’s operations since its effective bankruptcy in 2023, for the apparent lack of progress.

Unite general secretary Sharon Graham said Rayner had “had every opportunity to intervene and resolve this dispute”.

She added that the government’s backing for the “so-called Labour council” had been “disgraceful”. Unite says it has also suspended the memberships of Cotton and other Labour councillors.

“People up and down the country are asking whose side is the Labour government on, and coming up with the answer ‘not workers'” she added.

In a statement on X, Cotton said Unite had “repeatedly rejected reasonable offers” made by the city council to avoid “another equal pay crisis”.

Rayner, whose brief includes local government, has called on the union to accept a deal to end the strikes tabled by the city council, saying the authority had “moved significantly to meet the demands of the workers”.