Angela Rayner has suggested sexism is behind claims of a Cabinet rift over immigration plans.
The Housing Secretary dismissed evidence of tensions at the top of Government, saying people 'love saying us girls are all falling out'.
The comments, in a round of broadcast interviews, came after Energy Secretary Miatta Fahnbulleh attacked the Home Office's proposals to make immigrants wait years longer for 'settled' status.
In March Ms Rayner described the plans, championed by Home Secretary Shabana Mahmood, as 'un-British' and 'wrong'.
Peckham MP Ms Fahnbulleh wrote in an article on her constituency website: 'If we continually prolong the time people have to wait for settlement, we can also prolong the process of building cohesion.
'We need to raise the level of the debate, challenge divisive political rhetoric and make the case for communities like the one we have in Peckham. That means talking about immigration with care, control and compassion.'
Angela Rayner dismissed evidence of tensions at the top of Government, saying people 'love saying us girls are all falling out'
The article has now been deleted and is being updated, it is understood.
Ms Mahmood argued last autumn that it was essential to make foreign nationals – particularly those who arrived in the record post-Covid immigration wave – wait longer to secure settled status, also known as 'indefinite leave to remain' (ILR).
She warned that leaving ILR rules untouched would result in 'a £10 billion drain on our public finances' as migrants qualify for full access to benefits and social housing after winning permanent status here.
Asked about Ms Fahnbulleh's intervention this morning, Ms Rayner told LBC: 'They love saying us girls are all falling out, don't they?
'I mean, it's just not true. It's just not true.'
She defended Ms Mahmood's record on immigration, pointing to an increase in deportations and 48,000 small boat crossing attempts which the Government says have been prevented in the Channel since 2024.
'She's delivering, and she's had a consultation on it,' Ms Rayner said. 'She said she wants a fair process, and we're all up for that.'
Asked why she had attacked the proposals herself, she said: 'I literally made my views known as part of that consultation.'
Pressed on whether she supports what Ms Mahmood wants to do, she added: 'Absolutely. I'm absolutely in support that Shabana needs to tackle this issue.
'I mean, every single doorstep you go on, people say we want to secure our borders. We don't mind immigration that comes to this country. We celebrate immigration that comes to this country.
'We're proud to be a refuge for people who genuinely need to claim asylum here. But people want to have confidence that we know who's coming to this country, and we secure our borders.
'Shabana is doing that. She's tackling those issues, and she's been successful where previous home secretaries have not.'
Ms Rayner told Times Radio: 'I'm confident that Shabana will land in a place that is fair to the taxpayers, fair to people who come to this country, who contribute, who have been asked to come to this country and contribute.'
Under the current proposals, the baseline qualification period would double to ten years, while low-skilled foreign workers and anyone claiming benefits during that time would wait even longer.
The Daily Mail revealed on Monday more than 200,000 migrants have been granted ILR while the plans have remained in limbo since being first outlined in November.
According to Home Office estimates 1.6 million migrants are due to qualify for settlement between this year and 2030, although the figure could be as high as 2.2million.
It includes more than 450,000 who arrived here on 'health and care worker' visas, which have seen widespread abuse by bogus applicants.
Ms Fahnbulleh's online comments – relating to a constituency 'town hall' meeting she attended on September 25 – also said the 'political debate around immigration has become increasingly depressing and toxic'.
She urged her party to 'challenge divisive political rhetoric' on immigration, adding: 'Ultimately, I want to see a system based on control and compassion, with a much stronger focus on integration.'
Ms Rayner was critical of Ms Mahmood's proposals last month, saying in an interview they would 'change the goalposts' for migrants already in Britain. She highlighted foreign care workers in particular.
In March, while on the back benches, Ms Rayner went further and described Ms Mahmood's plan as 'un-British' and a 'breach of trust'.
The general secretary of Labour-affiliated trade union Unison, Andrea Egan, has also attacked the proposals.
Shadow Home Secretary Chris Philp said: 'Labour's Cabinet members are openly campaigning against their own Government's supposed immigration policy.
'Miatta Fahnbulleh says she opposes a longer time for immigrants to get permanent settlement – the opposite of Shabana Mahmood's claimed policy.
'Shabana Mahmood has already delayed implementing her own policy, allowing 200,000 immigrants to stay permanently and claim benefits. Instead of being tough as she said she would be, she is running scared of Angela Rayner and the Labour Left.'
Shabana Mahmood argued last autumn that it was essential to make foreign nationals – particularly those who arrived in the record post-Covid immigration wave – wait longer to secure settled status, also known as 'indefinite leave to remain' (ILR)
Energy Secretary Miatta Fahnbulleh questioned the Home Office's plans to make migrants wait longer for settled status - giving them full access to welfare and social housing - in a now-deleted article on her constituency website
Mr Philp added: 'Under this Labour Government, every day nearly 1,000 immigrants get the right to stay here permanently and claim benefits.
'The Home Secretary herself has admitted that this will ultimately cost taxpayers £10bn and be an 'affront' – in her words – to decent hard-working people.
'The permanent right to stay here should take 10 years to earn and only be available to high earners making a real contribution.
'Low-wage and no-wage migrants should be required to leave when their work visa expires. Only the Conservatives have a credible plan to do that.'
A Home Office spokesman said: 'This Government has announced reforms that mean settlement must be earned and not automatic.
'We are currently considering responses to our consultation on elements of these reforms.'
