Brown appeals to voters for five more years

The Prime Minister, flanked by his Cabinet, said in Downing Street: "It will come as no surprise to all of you - and it is probably the least well-kept secret of recent years - but the Queen has kindly agreed to the dissolution of Parliament and a General Election will take place on May 6.

"I come from an ordinary middle-class family in an ordinary town and I know where I come from and I will never forget the values - doing the right thing, doing your duty, taking responsibility, working hard - that my parents instilled in me."

He went on: "I'm asking you, the British people, for a clear and straightforward mandate to continue the urgent and hard work securing the recovery, building our industries for the future, and creating a million skilled jobs over the next five years."

Tory leader David Cameron pre-empted the official announcement with an off-the-cuff speech to enthusiastic supporters outside London's County Hall.

He declared this would be "the most important General Election for a generation".

And Liberal Democrat leader Nick Clegg insisted "all bets are off" as the nation prepares to decide the closest-run campaign since 1992.

The three party leaders hit the campaign trail immediately after Mr Brown's confirmation of polling day, fanning out across the country.

The day of traditional Downing Street drama began at 9am with a weekly Cabinet meeting in No 10.

Mr Brown was then whisked at 10am in a police motorcade to Buckingham Palace, arriving five minutes later.

The Queen had been flown in by helicopter from Windsor Castle, touching down at 9.50am ready to receive her Prime Minister and grant his request for Parliament to be dissolved on Monday.

After their 20-minute meeting, Mr Brown arrived back in Downing Street before emerging from No 10 with his ministers to make his formal announcement.

After confirming polling day, he said: "Over these last few months this Government, it`s fought hard, facing the biggest world recession, to fight on behalf of hard-working families on middle and modest incomes.

"Over the next few weeks I will go round the country - the length and breadth of our land - and I will take to the people a very straightforward and clear message - Britain is on the road to recovery and nothing we do should put that recovery at risk.

"There will be many big challenges and many big decisions to make over the next few months upon which our future success depends.