London:  British Prime Minister Gordon Brown defended his handling of the economic recovery on Monday as he prepared to fire the starting gun on a general election that opinion polls suggest he could lose.

Brown is expected to visit Queen Elizabeth II today to dissolve parliament and kick-start a month-long general election campaign culminating on May 6 in what many are predicting will be a close-run battle.

Campaigning has effectively been in full swing for weeks, but the looming official announcement will sharpen the fight in a contest where the Conservatives are bidding to oust Labour from power after 13 years in opposition.

While the outcome looks likely to be extremely close, one thing is clear-cut — the economy is set to be the dominant issue on the campaign trail.

As Labour insisted on Monday their National Insurance tax rise plans — opposed by the Conservatives — were vital to strengthen the public finances, Brown compared the economy to England football star Wayne Rooney's injured ankle.

Slipping back

The country has edged out of its longest recession on record but some economists still fear a possible "double dip" back into the red.

"Securing the recovery is the biggest issue facing our country," Brown said in his weekly podcast.

"After an injury you need support to recover, you need support to get back to match fitness, you need support to get back your full strength and then go on to lift the World Cup.

"With the economy, we're not back to full fitness.

"If we try and jump off the treatment table as if nothing had happened we'll do more damage to the economy - and frankly that means we risk a double-dip recession.

"I think that's a risk we can't afford to take."

The election winners have the dubious prize of having to tackle a crippling budget deficit of at least £167 billion ($254 billion, 188 billion euros).

With cuts to public services inevitable, the Conservatives, Labour and the third-largest party, the Liberal Democrats, are competing to win the voters' support as the safest pair of hands on the economy.

Conservative finance spokesman George Osborne hit back at the prime minister, saying: "With Gordon Brown now finally forced to call the election, the choice is clear.

"Labour's jobs tax and debt will stamp out the green shoots and kill the recovery. Conservative plans to cut wasteful government spending and stop the jobs tax will get Britain working."

The centre-right Conservatives, led by David Cameron, need a huge swing in their favour to claim a majority of seats under Britain's first-past-the-post electoral system.

They had established a commanding lead over Brown's centre-left Labour Party in opinion polls only to see that advantage melt away in recent weeks, raising the prospect of a hung parliament.

But polls at the weekend showed the Conservatives appeared to have re-established enough of a lead to give them a narrow majority in the House of Commons and make the telegenic, 43-year-old Cameron prime minister.

London (Reuters) The third biggest party in parliament, the Liberal Democrats, fired up its election battle bus yesterday.

The centre-left opposition party could hold the balance of power between Labour and the Conservatives if the election results in a hung parliament — where no one party has overall control — as opinion polls have suggested.

Liberal Democrat leader Nick Clegg arrived in a gold-coloured bus in the new London seat of Hampstead and Kilburn, one of several marginal seats that Labour will probably need to win to stay in power.

The Liberal Democrats, campaigning under the slogan "Change that works for you", claim they only need to win over a few hundred voters to beat Labour in the north London constituency.

"I just want to get on with the campaign," Clegg told media. "Let's get this campaign off to a really good flying start."