LONDON - A top deputy to Britain's troubled Prime Minister Gordon Brown is warning legislators seeking his ouster to end their rebellion -- or risk making the situation of the ruling Labour party more tenuous.

Business Secretary Peter Mandelson, appearing on the BBC's Andrew Marr talk show, urged party dissidents to think about the consequences of an ugly leadership battle. The tussle comes as voters are punishing Labour legislators for abusing their expense claims in a scandal that has shaken the government.

"Stop taking shots at the prime minister because you are simply going to make the position of the party and the government even worse," Mandelson said.

Brown, who took over from former prime minister Tony Blair after waiting more than a decade, has been battling desperately to keep his job amid a rebellion in the ranks. But Mandelson said that dumping Brown would trigger an election before the government could complete economic reforms.

"If we were to have a third leader in a single parliament it would mean irresistible pressure to hold a general election before we were able to carry out the changes in the economy," he said.

Brown faced a new crisis Sunday with the release of European election results rumoured to be disastrous for Labour. Senior party leaders fear that the results could be even worse than local elections that saw the party lose hundreds of seats and control of its last four English counties.

A result that sees Labour finish in third behind the two main opposition parties -- or even fourth behind the fringe Independence Party -- could fuel the rebellion. Party rebels may use a parliamentary Labour party meeting Monday to show whether they have the support to demand a leadership election.

At least one influential Labour legislator has rallied to Brown's support. John Cruddas wrote in the Sunday Mirror that simply dumping Brown is "madness" that won't solve Labour's troubles.

"We're now less than a year away from the election," Cruddas wrote. "We have no more chances left. We either pull ourselves together, stake out what we stand for, or we will be gone."

Meanwhile, Mandelson also faced beating back an embarrassing leak. The Mail on Sunday reported that in an email sent before Mandelson joined the government, he portrayed Brown as an insecure and angry man.

"He is a self-conscious person, physically and emotionally. He is not as comfortable with his own skin as Tony (Blair) was (is). A new public persona cannot be glued on to him," the newspaper quoted the email as saying.

Mandelson said the email was taken out of context.