Former Pakistan Prime Minister Nawaz Sharif has announced he will to return his country to challenge President Pervez Musharraf.
He told reporters as a news conference in London that he would return to Pakistan on 10 September, ending seven years of exile in Saudi Arabia and the UK.
His announcement comes as Mr Musharraf faces pressure from another ex-premier, Benazir Bhutto, to step down as army chief in a proposed power-sharing deal.
However President Musharraf rejected calls by Ms Bhutto for a quick decision on a deal, reportedly agreed in talks between the two, that would see him quit as army chief.
Mr Musharraf's official spokesman said the president would not react to pressure and dismissed media reports that Ms Bhutto had in fact delivered an ultimatum during the talks.
And Mr Sharif, who served as leader between 1990 and 1993 and again from 1997 to 1999, has condemned the proposed Bhutto deal as bad for the country and very unfortunate.
President Musharraf, who seized power in a bloodless coup in 1999, is under intense pressure to give up his army role but has said he still intends to be re-elected for another five-year term as a uniformed president.
