A bid to commit the Liberal Democrats to an e-petition system capable of vetoing unpopular new laws has been defeated at the party's annual conference in Bournemouth.

Supporters of the move said they fear some form of the proposal - under which a referendum on proposed legislation would be required if a million voters signed an e-petition to parliament opposing it - may now be taken up by the Tories.

Party activists supported a motion favouring replacing the existing paper-based petition system with one requiring MPs to consider issues which gain sufficient support, with the six most popular proposals each year guaranteed a full-scale debate in the House of Commons.

But they opposed the idea of allowing a reactionary majority of voters to delay or block progressive ideas, despite pleas to "trust the people", claiming it would be too easy for right-wing pressure groups to secure sufficient backing online.

Supporters said that giving switched-off younger voters a real say which could affect the outcome would help mend "broken" democracy.

The debate kicked off a conference at which party leader Nick Clegg and shadow chancellor Vince Cable made clear they would seek to ditch remaining delayed components of the NHS computer system, as well as drop the government's ID cards scheme to save money to fund other social objectives, including tax cuts.

The Labour government is committed to a watered-down version of a parliamentary e-petitions system - but probably not until after the next general election in 2010. The Tories have no official line.

On Wednesday this week, the Liberal Democrats will vote on plans to strengthen the powers of the Information Commissioner to include inspecting private as well as public sector databases containing personal information, and to increase civil and criminal sanctions for the misuse of personal data.