Prime Minister Gordon Brown spoke to Pakistan President Pervez Musharraf and urged him to "stick to the course" of democracy and stability yesterday following the assassination of opposition leader Benazir Bhutto.

Mr Brown called the killing a "cowardly terrorist act" designed to destabilise elections set for January 8.

"The international community is united in its outrage and determination that those who stoop to such tactics shall not prevail," Brown said in a statement released after he had spoken to Mr Musharraf by telephone.

"I therefore encouraged President Musharraf to stick to the course he has outlined to build democracy and stability in Pakistan."

Mr Brown emphasised Mr Musharraf's role as an ally of the US and Britain in their battle against al Qaeda and Taliban militants in Afghanistan.

"This deadly attack is also a potent reminder of the threat we face from terror. Pakistan is a major ally in the global effort to combat this menace," Mr Brown said.

"I told President Musharraf that the UK is prepared to sustain and build the already significant counter-terrorism support we offer his country, not least in the effort to destroy al Qaeda."

Mrs Bhutto, 54, was killed in a combined shooting and suicide bomb attack as she left a campaign rally in the city of Rawalpindi on Thursday.

No one has claimed responsibility for the attack, but Mr Musharraf's office blamed Islamic radicals linked to al Qaeda or the Taliban, and US President George W. Bush has also pointed the finger in that direction.