Launching the manifesto, Make the Difference, the Liberal Democrat leader said: "Our pounds 10bn programme of investment in education over the next five years will deliver real improvements in our children's education."
The manifesto offered new books and equipment for schools to the tune of pounds 110,000 more for a secondary school with 1,000 pupils, and an extra pounds 16,000 for primaries with 250 pupils; a cap of 30 on class sizes for children between five and 11; and a guarantee of nursery education for all children of three and four.
Mr Ashdown said: "As a nation, we cannot afford to let standards in our schools drop any lower."
The manifesto also contained a costed programme for the National Health Service; with more doctors and nurses, a six-month limit on the waiting time for hospital treatment and free eye and dental checks.
Mr Ashdown and colleagues hit a hitch on the section of the manifesto describing the policy to redistribute pounds 1.4bn from the 140,000 people with taxable income of more than pounds 100,000 to finance an increase of pounds 200 in the income tax threshold, taking 470,000 low-income people out of tax. The manifesto said: "This will provide lower taxes and new incentives to work, while cutting the benefits bill and reducing tax for 99.5 per cent of all income taxpayers."
In fact, when a 1p increase in income tax rates is taken into account, the measure needed to finance more education spending, half the remaining 25 million taxpayers will be worse off. But that is not made clear for another 14 pages of the manifesto.
Mr Ashdown says in a foreword: "Eighteen years of Conservative government have left our society divided, our public services run down, our sense of community fractured and our economy under-performing."
He complained of a fatalism infecting politics. "Though the challenges are immense, the solutions we are offered are all too often puny," he said.
"We are told we can't ask people to pay more for a better education. Or change the way we live to protect our environment. Or share more to give better opportunities to those who have less. Or modernise our politics to give people more say.
"The Liberal Democrats reject this timidity. We are in politics not just to manage things but to make things happen."
Mr Ashdown said on BBC Radio 5 Live that in local government his party was responsible now for pounds 18bn of public spending. And he told Radio 4's Today programme his party would be willing to work with others in the new Parliament: "We are fighting for every seat and every vote in this country and what happens the other side of the election will depend on the result of the ballot box."
But on the same programme, Kenneth Clarke, the Chancellor, dismissed the Liberal Democrat manifesto promises as "third-party flannel".Reuse content