Nicol Stephen believes the Lib Dems are the party will momentum

Mr Stephen is the current deputy first minister in the Scottish Executive's Labour-Lib Dem coalition.

He told a gathering at the Scottish Liberal Democrat's autumn conference in Dunfermline that his party was aiming to win next year's Holyrood poll.

Mr Stephen promised a unique programme of policies that would improve education, environment and the economy.

He said the party had "torn up the rule book that said we must always be the minority party".

If I become first minister we will deliver a nation and an economy that every talented, creative, innovative person and every young person across the world will want to be part of Nicol Stephen Scottish Lib Dem leader

And he added: "All our strategy, all our ambition, all our campaigning between now and next May must be for the Liberal Democrats to be, for the first time in our history, the largest party in the Scottish Parliament."

Mr Stephen insisted: "We are the party with momentum in Scotland, gaining support amongst young people, winning votes in new parts of Scotland, perplexing pundits, mystifying the media, but energising the electorate with fresh hope and fair ideals."

He also used his speech to set out some of the policies a future Lib Dem Executive would implement.

Mr Stephen pledged that Scotland would make a "green switch" to renewable energy, and restated his ambition for all of Scotland's electricity to come from such sources by 2050.

Private sector backing

He revealed plans to set up a new investment agency, called the Scottish Investment and Innovation Agency.

This would bring together investment and research and development support from government and universities, and would in turn help attract more private sector backing.

"We need industry, government and education to cooperate more strongly than ever before," he said.

"If I become first minister we will deliver a nation and an economy that every talented, creative, innovative person and every young person across the world will want to be part of."

The Lib Dem politician also used his speech to the day-long conference to attack his political rivals in the SNP and the Tories.

He said it was the "same old story" with the Nationalists, telling delegates: "They predict victory and then they lose".

Likewise he said the Scottish Tories had not changed, saying they had the "same old faces, same old policies, same old Tories."

And like his UK leader, Sir Menzies Campbell, Mr Stephen also spoke out against the war in Iraq, criticising Prime Minister Tony Blair for his support of the US invasion.