The United Nations may be unlikely to agree to tough action against Zimbabwe, the foreign secretary has warned.

Jack Straw told MPs on Tuesday that despite the deteriorating situation under Robert Mugabe's regime, the United Nations could end up following the same sequence of events seen during the Iraq crisis.

He argued that if the international community failed to unite it would hand a propaganda victory to the Mugabe regime.

"I would be the first to have this taken before the security council if I thought we could have a safe outcome. If we were to try and were to fail, that would plainly be regarded by Mugabe as a victory for him," said Straw.

His comments followed a meeting of senior African leaders which had sought to engineer Mugabe's retirement.

While the outcome of those talks was inconclusive, the foreign secretary has warned that the crisis is threatening to destabilise the region.

"I am in no doubt that those three heads of government are fully aware of the damage that the Mugabe regime has done," he said.

His comments followed accusations by shadow foreign secretary Michael Ancram that the government was "walking by on the other side".

For the Liberal Democrats, Menzies Campbell also called for action because "some of the poorest people in Africa have to pay for the excesses of the Mugabe regime".