Tory leader David Cameron clashed angrily with the Prime Minister over the budget deficit today, insisting there was a need for spending cuts.
In the feverish run-up to a general election, Gordon Brown warned that Tory policies would take Britain back to the 1980s, with cuts to education and police services.
As the row escalated at Commons Question Time, Speaker John Bercow intervened, reminding MPs: "We're not on the hustings now."
Mr Cameron took up the challenge, saying: "I wish we were. I wish this Prime Minister had the courage to call the election and we could get on with it."
Mr Brown repeatedly taunted the Opposition leader over the apparent confusion on Monday over the Conservatives' policy on recognising marriage in the tax system.
To laughter, Mr Cameron told the Prime Minister: "The difference between me and you is this - when I lean across and say 'I love you, darling', I really mean it.
"The only divorce that's taken place is between you and reality."
But Mr Brown hit back, saying: "For you to talk about love and marriage today, when you are the person who cannot give a straight answer on the married couple's allowance - whether you can say 'I do' or 'I don't' on it."
The row erupted after Mr Cameron said the Government would have to borrow £178 billion this year.
"Yesterday one of the largest holders of Government debt warned that British debt is likely to be downgraded.
"The OECD, the CBI and the Bank of England have all warned there is no proper plan to deal with this deficit.
"Why do you think all these people take that view?" he asked.
Mr Brown said the issue had to be put in context.
"The debt of every country has risen as a result of a global financial recession.
"Debt in Britain is actually lower as a percentage of national income than America. It's lower than France and Germany. It's lower than Italy and Japan. It's lower than the average for the euro area.
"Every country faces the difficulty of taking its country out of recession, while at the same time having to develop a deficit reduction plan."
He told the Tory leader: "We won't stop the fiscal stimulus before we are out of recession.
"We won't take your advice and leave the economy without the support that is necessary.
"If we had taken your advice, many thousands more would be unemployed and many thousands of businesses would be lost."Reuse content