Charles Kennedy called yesterday for MPs to be given the right of veto over plans to send troops into battle abroad.

The Liberal Democrat leader backed demands for a British equivalent of America's War Powers Act of 1973, which requires the US President to gain the permission of Congress before authorising foreign military action. With the Government on the verge of deploying more than 30,000 troops to Iraq, he said it was "high time" for this "highly desirable" reform to the Constitution.

Mr Kennedy said: "Elected members of Parliament must have the right to make decisions which involve the lives of our citizens and thousands of others."

Several Labour MPs have backed the introduction of a War Powers Act and the Commons procedure committee is investigating proposals to give the Speaker the authority to demand Parliament's recall in times of national emergency.

Although Tony Blair has promised MPs would be allowed to debate any military action, he has insisted that the Government should be able to protect troops' safety by reserving the element of surprise in any attack.

Mr Kennedy's demand came in a lecture in London to a Liberal think-tank, the Centre for Reform, in which he renewed his call for a drive towards "genuinely democratic decision making" in Britain. He said: "It is no wonder people are losing faith and interest in politicians when they see parliamentary democracy so often and readily bypassed."