Image copyright PA Image caption Lord Ashdown is backing a cross-party movement to support centre-left candidates

The Liberal Democrats need to build alliances with centre-left "progressives" to defeat the Conservatives, Lord Ashdown has said, saying the party cannot do it alone.

The ex-Lib Dem leader said the party should be at the heart of a wider movement for progressive politics.

He also said the Lib Dems should be exploiting new technologies to connect with a broader audience.

The party had been "dawdling behind" the technological revolution, he said.

Speaking at a fringe meeting at the party's conference in Brighton, Lord Ashdown said the party needed to re-establish itself after its 2015 general election defeat - which saw the party reduced to just eight MPs - and show that it was once again a "rising force" in politics.

He was "utterly confident" the party could recover, "but to what purpose?"

'Reach out'

He said it was "not good enough" just to want to remove the Conservatives from power, and their ambition should be to put a "progressive government" in place.

But he added: "Can you do that alone? No... You have to reach out to others."

"If you are going to overturn this government for something better you have to build a relationship beyond the Liberal Democrats to give this country an alternative modern progressive government."

Image copyright PA Image caption The Lib Dems can learn from how Jeremy Corbyn has mobilised support, the ex-leader said

One way to do this, he argued, was by taking advantage of new technologies, such as social media, to reach out to a broader audience and engage people who are interested in politics but not necessarily political parties.

But he said the Lib Dems were "dawdling behind" the technological revolution, in contrast to UKIP, the Greens and Momentum - the Jeremy Corbyn-supporting pressure group - which he said had tapped in to its potential.

'Investing in winners'

Lord Ashdown said he believed there was an appetite for a "people's movement" to be at the "service of the progressive centre left" - and he said this was what the cross-party More United Project, that he helped to set up, was designed to achieve.

He said it had attracted 38,000 members in six weeks and predicted its membership would hit 100,000 in a year.

"There isn't a people's movement serving the progressive forces of British politics. More United is designed to be that.

"It's designed to be for people who believe what we believe and want to make a difference."

He said its principles were entirely compatible with Lib Dem values, and its intention was to support candidates representing the centre-left of politics in about 50 parliamentary constituencies.

But he stressed that it was not a political party, likening it instead to the National Lottery, "picking and investing in winners".

Its members should be seen as "assets" to the party, not a "threat", he added, saying he was "utterly confident" the movement would "benefit" the Lib Dems.

However, he said it wasn't enough for the Lib Dems to boost their numbers in the Commons if the Conservatives remained in power.

"If you can assemble a wider movement around the Liberal Democrats, in which we are the fulcrum that can deliver progressive government to the country, that's victory.

"Thirty seats, with the largest party the Tory party, is I'm afraid not a victory that's good enough for me."