WASHINGTON, June 25: For the first time since the occupation of Iraq, a poll released on Friday showed that a majority of American citizens now believes the invasion was a mistake.

This big swing in US public opinion against the invasion - depicted in the latest Gallup-CNN-USA Today survey - followed a sudden increase in attacks on US forces and their allies in Iraq.

The 54 per cent negative assessment of the invasion is the first time since Vietnam that a majority of Americans has called a major deployment of US troops a mistake. Last year, when the invasion of Iraq began, the public by three-to-one said sending troops was not a mistake. And just three weeks ago, 58 per cent still held that view.

The predominantly negative assessment includes a new feeling by the majority the occupation has made the nation less safe from terrorism.

A Washington Post/ABC News survey earlier this week also showed that President Bush was rapidly losing support over the occupation but a thin majority - 51 per cent - still believed the war had made them safer.

The Gallup poll has surveyed US public opinion on Iraq on six earlier occasions since March last year. During the first days of the invasion, 75 per cent of Americans said they felt military action was the right course; since October, between 40 and 44 per cent of those polled have said military involvement was a mistake.

The survey also showed that concerns about the occupation are not yet affecting party loyalties.

Most traditional Republican and Democrat voters are still determined to vote for their party nominees, war or no war.