The UK's involvement in the Iraq war has been cited as the reason behind a sharp drop in support for Labour among Muslim voters.

In a special poll for the Guardian by ICM, 38 per cent of those questioned said they continued to support the Labour Party, compared to 75 per cent at the last general election.

Liberal Democrats come a close second among Muslim voters at 36 per cent, while a quarter would vote Conservative.

Speaking to the Independent, Liberal Democrat leader Charles Kennedy argued that Tony Blair has lost a level of trust he once had with voters.

"I think it's very difficult for the prime minister to regain the level of trust that existed a few years ago. Very difficult indeed," he said.

"That may be the inevitable consequence of events or the passage of time, but it strikes me that there is just a fundamental sense out there that you can't quite be certain that what you are being told is accurate. And that is very corrosive for a government - any government."

Opposition to the Iraq war remains high one year after the beginning of the US-led invasion, at 80 per cent. Although 73 per cent of those questioned said they were strongly opposed to terrorist activity by al Qaeda and other organisations, 13 per cent answered that further attacks on the United States would be justified.

In contrast, the regular ICM poll for the Guardian found public opinion evenly split, with the majority of those questioned believing that British troops should remain in Iraq for as long as is necessary.

According to this survey, Labour retains a two-point lead over the Conservatives, with Liberal Democrats continuing in third place.