Mr Brown argued that Labour's moral vision of a fairer society was now an economic necessity in a global battle for skills.

In his speech to the Scottish Labour party conference in Aviemore, near Inverness, he said: "We used to talk about the arms race. Now we have a skills race around the world."

And he declared: "We will stand up to the SNP not only because their policy is wrong but they are depriving people of the best chance of a future for Scotland in this new global economy."

His first speech as Prime Minister to the Scottish Labour conference was a rallying cry to a party still coming to terms with life in opposition after last May's election saw it ejected from power at Holyrood and a swathe of local councils.

It was also a public endorsement of Scottish Labour's new leader, Wendy Alexander, whose party is still finding itself lagging behind the SNP in opinion polls.

Mr Brown said: "I have known Wendy for many years. She is a long-standing supporter of devolution. She has a passion for equality and social justice."

He went on: "She has told us we have to listen to the people of Scotland more. She has told us we have to be prepared to reform and modernise.

"And I believe that Wendy Alexander is not only the leader of our party here in Scotland but she will be the next First Minister of Scotland whenever an election is declared."

He had one policy announcement - an extra £120 million is to be spent helping athletes train for the 2012 London Olympics and the 2014 Commonwealth Games in Glasgow.