Chancellor Rachel Reeves has ruled out "tax and spend" policies as she prepares to deliver her much-anticipated Spring Statement on Wednesday.
Speaking in a BBC documentary, The Making of a Chancellor, Ms Reeves warned that the government could not afford spending increases seen under the last Labour government.
She said: "We can't tax and spend our way to higher living standards and better public services. That's not available in the world we live in today."
The government has ruled out further tax rises after a record £40billion package in the October Budget, but the chancellor is under pressure to fill a £20billion hole in public finances.
She is struggling to meet her own financial rules following high-than-expected borrowing costs and stagnant economic growth.
The statement on March 26 is expected to include spending cuts including business rates and a relief in employers' national insurance contributions.
The Office for Budget Responsibility (OBR) will also publish its five-year forecasts for the economy and public finances this week.