Charles Kennedy has described the Conservatives as no longer relevant to most voters.

The leader of the Liberal Democrats has also insisted that only his party can mount a serious electoral challenge to Labour.

Addressing the Scottish Liberal Democrats conference in Glasgow, he said support for the Conservatives had fallen in a series of elections.

"They are reduced in the minds of voters, when given the opportunity, to near-irrelevance and they have been comprehensively rejected every time the voters are asked to return a new MP," said Kennedy.

"That's Michael Howard's Conservative Party for you - it is a busted flush, and it's a busted flush because the Liberal Democrats are seen to be the effective opponents and challengers to Labour at Westminster."

Kennedy also urged his troops to target the Scottish National Party.

He said the SNP was uncertain about how to make the most of devolution.

"Do they want devolution to work, do they want to contribute to that process in a responsible, constructive way, so that Scotland steps out that bit taller, sharper and better?" he asked.

"Or do they want this parliament, once described by their recycled leader as a pigmy parliament, to fail so that people lurch in a more extreme direction?"

Ahead of the next general election, Kennedy also said his party would mount a serious challenge to Labour as well as the Conservatives.

"This really is, across the UK, going to be an election of three party politics, and we are one of the top-table players in that general election."