GORDON Brown has urged voters not to put Britain's "fragile" economic recovery at risk by entrusting control to his "novice" rivals.

As official figures showed the economy continued to grow in the first three months of the year, the Prime Minister claimed 1.7 million more jobs would have been lost in the recession if the Tories had been in power.

The Conservatives however said that it was a "jobless recovery" which would see unemployment rise if Labour's planned increase in national insurance contributions went ahead.

After the second televised leaders' debate failed to produce a decisive winner, the two main parties returned to the familiar battleground of the economy which dominated the first week of campaigning. Preliminary figures from the Office for National Statistics showed the economy grew by an estimated 0.2% in the first quarter of 2010 - not as strongly as had been expected, but still avoiding a "double dip" recession.

Mr Brown said it was the wrong time to take chances as he sought to portray himself as the man with the experience to take right decisions in contrast to Tory leader David Cameron and shadow chancellor George Osborne.

"Our hard-earned recovery is too fragile to let these novices play with it now," he said in a campaign speech to students in Coventry. "Never were experience and judgment more called for than now." He said that it was the Tories' lack of economic credibility, as much as Liberal Democrat leader Nick Clegg's "TV and PR skills" that had put paid to the idea that the election was "an inevitable Tory procession to Downing Street".

Earlier, at news conference in London, Mr Brown vowed to "fight as though my life depended upon it" to ensure a Labour victory, while Business Secretary Lord Mandelson mocked Mr Cameron and Mr Osborne as "just a couple of kids in school shorts".

Mr Osborne however said that the "disappointing" growth figures showed that Britain still had deep economic problems.

"After the longest recession we now have a jobless recovery from a weak Government," he said. "What Britain doesn't need now is a jobs tax that would kill the recovery or a hung parliament that would lead to economic paralysis."

Liberal Democrat Treasury spokesman Vince Cable said that the recovery was "barely visible" and could still fall away. He said: "There is a real danger of the UK going into a double dip recession."