Jemima Khan [Images] will join her former husband Imran Khan [Images] at a demonstration against Pakistan President Pervez Musharraf [Images] in London [Images].

The British socialite, who has been vociferously criticising Musharraf since he arrested Khan after imposing emergency in Pakistan, will be at 10, Downing Street chanting slogans when the Pakistani leader meets British Prime Minister Gordon Brown on Monday.

"I will be protesting against Gordon Brown's continued support for Pakistan's dictator. I will be joined by politicians, lawyers, doctors, human rights activists, journalists and ordinary Pakistanis," she told the Sunday Express.

"We want to know why our Prime Minister is hosting a constitutionally illegal leader when many hundreds of political activists, lawyers and judges in Pakistan remain in prison or under house arrest and when the media there is still restricted," she said.

On the last day of his 4-day visit to the United Kingdom, Musharraf will meet Brown and later address a news conference.

Ever since he reached London on Friday, Musharraf has been facing a spate of demonstrations organised by human rights campaigners and opposition parties.

Imran Khan, who heads Pakistan Tehreek-e-Insaf party, specially flew in here to participate in the demonstration.

Jemima, who had lived in Pakistan during her 9-year marriage to Imran, cast doubt on Musharraf's promise to hold fair and free elections.

"Sixty per cent of the superior court judges have been sacked by Musharraf and many are still under house arrest. There is no chance of free and fair elections under the supervision of hand-picked substitute judges, a pet caretaker government and a bogus election commission," she said.