Pledging to raise the top rate of income tax to 50% for high earners and add a penny to the basic rate to fund education, Mr Kennedy said "fair and modest" increases were necessary for quality public services.

We're the party which actually says to people, fairly and squarely, 'look folks, you can't get something for nothing'

Charles Kennedy

With the additional billions of pounds, he said, "you can substantially increase pensions, you can put a lot more money into education, cutting class sizes and getting rid of tuition fees... and you can provide more investment for the health service."

The comments were made as the leader's battlebus stopped off at a May festival in Portsmouth South - a constituency the party won from the Tories at the last election.

'Opportunity'

Mr Kennedy said his first campaign as leader would be "a great opportunity to put over a distinctive message".

"We're the party which actually says to people, fairly and squarely, 'look folks, you can't get something for nothing... there has to be a price tag attached'".

Mr Kennedy said the "false opposition" between Labour and the Conservatives would fail to impress voters, and predicted the Lib Dems would increase their total of MPs, currently 47.

Earlier, foreign affairs spokesman Menzies Campbell said extra spending on schools, hospitals and pensioners would be placed at the heart of the Liberal Democrats' campaign.

We need more investment, more quickly in services such as health, education and a better deal for pensioners

Menzies Campbell

'Real change'

Mr Campbell said: "People are disappointed with Labour and continue to distrust the Conservatives, so this election will provide an opportunity for real change in Britain.

"The message is clear. We need more investment, more quickly in services such as health, education and a better deal for pensioners.

"The more seats the Liberal Democrats win, and the more votes we get, the more of these aims we will achieve," he added.

On Tuesday Mr Kennedy and home affairs spokesman Simon Hughes used a school visit to repeat their pledge to provide extra investment in education.