Charles Kennedy opposed the build-up to war

But the Liberal Democrat leader added that although military action was now under way "I do not think any of us should abandon our critical faculties" with regard to the war's immediate aftermath and the role of the UN and European Union in Iraq's future.

Speaking to journalists at Westminster, Mr Kennedy said that the "health of the body politic" had been proven to be in a good state - although it was "awful" that it had taken a war to demonstrate it.

"If the Iraq situation has shown one thing, it is that there is a degree of re-connection with politics," he said.

In an "age of apparent cynicism and dislocation", people across the country - including the young - had been re-engaged with what went on at Westminster.

Recent weeks had also reaffirmed the primacy of Parliament in the nation's affairs, with a "reassertion of the House of Commons", according to the Lib Dem leader.

"I just hope the politicians can live up to that," he added.

Asked whether he had been hurt by the rough ride he and his party had received from Labour and the Conservatives over his own parties opposition to the war, he said: "No, not at all."

The Lib Dems' opposition to war, which has matched public opinion, has coincided with a rise in its poll ratings recently.

But Mr Kennedy firmly rejected charges of opportunism. He pointed to his party's approach to asylum, on which he accused Labour and the Conservatives of pandering to populism.

Earlier on Thursday, soon after the first skirmish was confirmed, Mr Kennedy said: "Now that the opening stages of military action have begun, we must all hope and pray that it can be concluded as swiftly as possible, with minimal casualties for all concerned.

"My thoughts are particularly with our British service personnel who are in the Gulf and their families here at home."

Throughout the long build-up to war Mr Kennedy has been the only mainstream party leader to oppose military action, insisting that he would remain critical of Mr Blair's approach until the first bullet was fired.