Chancellor Gordon Brown is facing a Commons vote of no confidence over his handling of occupational pensions.
Labour's majority should ensure that Mr Brown will comfortably survive the vote on a motion tabled by the Conservatives.
But the Tories hope that their decision to use one of their opposition days to debate his 1997 Budget decision to scrap tax relief on pension funds will again focus attention on a subject on which he is highly vulnerable.
It follows the recent release of Treasury documents under the Freedom of Information Act, which sparked claims that Mr Brown ignored the advice of officials when he abolished the relief - a claim the Treasury denies.
Shadow chancellor George Osborne said: "This is Gordon Brown's chance to explain why he sought to hide the dangers of his reckless raid on pensioners' savings.
"After the revelations about the raid, how can anyone have confidence in his judgment? We shall see if the Chancellor has the political courage to apologise to the millions of pensioners affected."
The Treasury has confirmed that Mr Brown will respond to the Tory motion.
It is highly unusual for opposition parties to table no confidence motions against individual ministers in this way - particularly if they have no realistic chance of winning.
However, the Tories appear to have made a tactical judgment that it is an effective way to step up pressure on Mr Brown ahead of his expected succession as Prime Minister when Tony Blair steps down later this year.
