Tensions are rising at the very top of the Labour government after it emerged Rachel Reeves and Angela Rayner could be going head-to-head over the amount of funding available for social housing.

Ms Rayner, the Deputy Prime Minister and housing secretary, has been trumpeting her ambitious target to build 1.5 million homes across the UK in the next five years.

But even before any spades have gone into the ground, the Chancellor Ms Reeves is understood to be considering tightening the purse strings and sources have said there will not be enough money for an “an immediate cash injection”.

Ms Rayner, who said house building was a “moral mission” for Labour could be disappointed by her colleagues at the Treasury when the Budget is announced at the end of this month, The Guardian reports.

it is understood Ms Rayner had asked for immediate top-funding to an affordable social homes programme which is expected to need £11.5bn of taxpayer cash over the next five years.

However, a Downing Street spokesperson said: “Not every department will be able to do everything they want to. There will be tough decisions taken, there will be tough conversations, but ultimately, this government has been very clear that it will fix the foundations.”

A Treasury spokesperson added: “No final decisions have been made but as the chancellor set out in July, the government is taking action to get Britain building again including building 1.5m homes over the next five years.”

This could mean dissappointment for Ms Rayner, who said at the Labour conference in Liverpool last month: “I actually think it’s a moral mission with the Labour government to recognise the problem and to build the social housing we need … But hopefully at the spending review, you’ll see that this government is really serious that we’re going to build those houses we desperately need.”

It’s been reported Ms Reeves has been taking an axe to government departments since she took over the role as Chancellor, with each division being told to shave a remarkable 10 percent off their capital budgets despite Labour promising more public services.

Ms Rayner, who along with Ms Reeves, was regularly pictured with Sir Keir Starmer duing the election campaign, has written to the Prime Minister protesting to the cuts.

She has been joined by Transport Secretary, Louise Haigh, and the Justice Secretary, Shabana Mahmood.

Kate Henderson, the chief executive of the National Housing Federation, said: “To deliver affordable and social housing at the levels needed, at the autumn budget we need… an urgent top-up in affordable housing funding, and commitment to a new multi-year affordable housing programme which prioritises funding for social rented homes.”