John Swinney said Scotland must flourish on the European stage

During his keynote address to delegates at the party's conference in Aberdeen, he said the SNP supported the idea of a European Constitution.

But he warned it would have to protect Scotland's interest and not sacrifice the fishing industry to Brussels.

Mr Swinney was launching the SNP's European election campaign.

He contrasted the ambitions of the countries due to join the European Union with that of the Scottish Executive.

Our values and our national interests are the guiding lights which steer the SNP's view of Europe John Swinney SNP leader

Mr Swinney said the countries were "brimming with enthusiasm" while the executive aimed to promote Scotland as a leading legislative region within the EU.

"When will these people ever get it? Scotland is not a region, it is a nation," he said.

"We demand the power of nationhood to proclaim our values and to defend our national interests.

"Our values and our national interests are the guiding lights which steer the SNP's view of Europe."

'Sovereignty' call

Mr Swinney said Prime Minister Tony Blair would have to stop Brussels' control of Scotland's fishing industry if he wanted to win a referendum on the constitution.

The SNP leader said: "To win that referendum, Tony Blair needs to win in Scotland.

"To win in Scotland, he needs the support of the SNP. And he will only win the support of the SNP if he vetoes the absurd plan to hand over Scotland's fishing industry to Brussels.

"Those are the terms of our deal."

The SNP leader received support for his internal reform package

Mr Swinney also criticised the UK Government over its decision to go to war in Iraq.

"On June 10, in the European elections, we can send a clear message to the government," he said.

"You cannot lie to the people, you cannot engage in illegal war."

Earlier, Mr Swinney received support for his internal reforms package.

A majority of delegates endorsed his proposal to introduce one-member-one-vote to choose the party leader and parliamentary candidates.

He also won crucial arguments on delegating responsibility and gender balance as he seeks to reform the party constitution.

Putting forward his one-member-one-vote argument on Saturday, he said: "If we believe in the sovereignty of the people of Scotland to decide our future, surely we should believe in the sovereignty of the party membership to determine the key issues that affect the governance of our party."

Every person who joined the SNP should have the chance to be involved in the decision making process, he added.

But Christine Grahame, region MSP for South of Scotland, raised concerns over the move.

"What I am concerned about is whether or not it is an informed vote," she said.