Married couples should not "count on" the Government delivering them tax breaks before the 2015 general election, Cabinet minister Kenneth Clarke said.
Conservatives fought the 2010 election on a promise of a transferable tax allowance that could be worth £150 a year to married couples where one spouse stays at home.
But the measure was opposed by Liberal Democrats, who secured the freedom under the Coalition Agreement to abstain in any parliamentary vote on the issue, and Mr Clarke has indicated in an interview with the Daily Telegraph that tough economic conditions made it unlikely to be introduced before the next election.
Despite the better-than-expected growth of 1% in the third quarter of 2012 announced earlier this week, Mr Clarke said it was too early to be certain the economy is bouncing back.
Saying that he believes a "long hard road" still lies ahead, Mr Clarke indicated that married tax allowances may be a casualty of the tight economic conditions.
"We never committed ourselves to married couples' tax by the end of the Parliament," the minister without portfolio told the Telegraph. "I'm married, I'm not counting on it. I don't remember anyone promising that kind of thing."
On the economy, Mr Clarke - a former chancellor - said: "It would be absolute folly to turn around and say it will all be fine by Christmas. Anybody who says we are absolutely certain we are bouncing back to strong growth is being very optimistic."
And the committed europhile sent out a warning to Conservative colleagues that they should not open up the debate about British withdrawal from the European Union.
Prime Minister David Cameron has said he will seek a "fresh settlement" of Britain's relations with the EU after the election, but Education Secretary Michael Gove was recently reported to have gone further by suggesting that the UK should use the threat of possible withdrawal as a weapon in negotiations.
Mr Clarke said: "To start threatening, throwing into the air our relationship with the outside world, with the global economy, would I think be very reckless. I frequently say that to several of my colleagues: there seems little point in opening up the debate at the moment about our membership of the European Union."