Chancellor Rachel Reeves is expected to reveal the state of the nation's public finances on Monday.
Ms Reeves is expected to raise autumn taxes to prepare the public of a £20billion "black hole" in finances, highlighting the current pressure the new Labour government is facing.
A Labour source said: "The British public are finally going to see the true scale of the damage the Conservatives have done to the public finances."
“They spent taxpayers’ money like no tomorrow because they knew someone else would have to pick up the bill. It now falls to Labour to fix the foundations of our economy and that work has already begun.”
The government said that it must spend extra money in order to keep public services alive.
The Treasury is expected to publish an unvarnished assessment of the public finances based on the latest figures from every department, with Ms Reeves revealing these results on Monday.
The Chancellor attended the G20 summit in Rio De Janerio, saying that the statement she will make to Parliament on Monday would show "honesty" about the the challenge Labour are currently facing.
Ms Reeves is likely to accept some above-payment settlements for public sector workers.