Nick Clegg called the Liberal Democrat manifesto "an insurance policy against a government lurching off to the extremes" after the election.
The Lib Dems have pledged to increase funding for education from "cradle to college", which they claim will mean spending £5 billion a year more than the Tories and £2.5 billion more than Labour by 2020.
Deputy Labour leader Harriet Harman says no one would believe the Liberal Democrat's manifesto promises because they broke their pledge to protect university tuition fees.
A ComRes/ITV News poll suggests a huge fall in support for the party in its south-west "heartland" - with the Tories benefiting most.
The manifesto launch was held in a "creative space", a bit like a trendy bar. But this is serious stuff though.
The Lib Dem 'cradle to college' pledge and theme of "opportunity" is one of of five policies featured on the front of the party's manifesto.