The pair are set for a clash over high-cost manifesto pledges which could be derailed by the economic crisis unleashed by the pandemic.
It comes amid claims a commitment on the pensions “triple-lock”, which sees the benefit rise by the highest of 2%, inflation or average wage rises, could be scrapped.
“Pensioners are going to be doing extremely well. It’s not politically that difficult a thing to smooth it out for a year,” a source told the Sunday Times.
The Chancellor and Prime Minister are also said to be at loggerheads over a social care overhaul which could cost £5billion a year.
A row is also brewing of the financing of the £200million National Flagship – seen as a replacement for the Royal Yacht Britannia.
An official described funding for the vessel as “a complete and utter s***show”.
The Northern Powerhouse Rail project to link key towns and cities across the region could also be in the Treasury’s crosshairs, it was reported. Northern Powerhouse Partnership director Henri Murison said: “Rumours that this commitment will be broken are deeply concerning for Northern leaders who are working towards rebalancing the economy.
“The North was promised HS2 and Northern Powerhouse Rail in full – to be abandoned now, just as we begin a recovery from the pandemic, would be a hammer blow.
“We need reassurance and certainty that there is no substance to these rumours, which means an Integrated Rail Plan published before the summer recess.”
Shadow Chief Secretary to the Treasury Bridget Phillipson said: “Incredibly, the Prime Minister has been the driving force behind huge amounts of wasted money and vanity projects without consulting his Chancellor.
“Uncosted promises are starting to catch up with both him and the Chancellor, and they’re leading to even more poor short-term decisions that store up long term problems – like blocking crucial investment in our children’s future and recovery.”
A Government spokesman said: “The Prime Minister and Chancellor work closely together, and have been in lockstep throughout the most challenging period any government has faced since the Second World War.”
He added: “We always ensure that all government spending provides value for money for the taxpayer.”