Rachel Reeves will splash the cash today as fears mount that Brits will need to pick up the bill later.
The Cabinet is set to sign off the spending review before the Chancellor announces the details in the Commons at lunchtime.
She will allocate huge sums to departments for the coming years, after loosening the government's borrowing rules at the last Budget.
But although Ms Reeves will boast that her new approach means Labour can spend a staggering £300billion more over the next five years than the Tories planned, critics have warned she does not know where the money is coming from.
The generous fiscal envelope set last Autumn has been put under massive pressure by the economy slowing down and Donald Trump's trade war.
