Pakistan's opposition has condemned an announcement that President Pervez Musharraf will seek to stay in power after his current term expires in 2007.
Musharraf reneged on a promise to resign as army chief
Supporters of Nawaz Sharif, the prime minister Gen Musharraf ousted in a 1999 coup, said the move exposed the president's "dictatorial designs".
A presidential spokesman predicted on Tuesday that parliament would give the general a mandate beyond 2007.
Opposition parties say this would be illegal and unconstitutional.
The constitution states that the next president must be a civilian elected through the parliamentary system.
The BBC's Zaffar Abbas in Islamabad says the intention of Tuesday's announcement appears to be to judge the public mood rather than make any clear commitment.
The president does not have sufficient support in parliament to amend the constitution by the required two-thirds majority.
Gen Musharraf, who reneged on a deal to stand down as army chief at the end of last year, would not be assured of victory even if he left his army post to contest the presidency, our correspondent adds.
'Dictator from top to toe'
Pakistan's opposition parties, usually far from united, were as one in opposing the president's latest move.
"He is a dictator from top to toe and so far he has not shared power with the rubber stamp parliament or the cabinet," Siddique-ul-Farooq, a spokesman for the pro-Nawaz Sharif faction of the Pakistan Muslim League (PLM-N), told the Associated Press.
Musharraf can rely on support from the US
Farhattulah Babar, of the Pakistan Peoples Party of former premier Benazir Bhutto, said Gen Musharraf's move hardly justified comment.
"He has already occupied the presidency through a fraudulent election and through unconstitutional means," he told the Reuters news agency.
A leader of the six-party Islamic MMA alliance, Liaquat Baluch, said: "This statement is a deviation from the constitution because even the present position of Gen Musharraf is legally and constitutionally controversial."
Gen Musharraf declared himself president two years after his military coup. He subsequently won a highly controversial referendum to stay on as president until 2007.
The poll was marred by widespread reports of vote-rigging.
The general's seizure of power was initially condemned by the international community, but he later became a vital ally to the United States in its war on terror.
Information Minister Sheikh Rashid announced the general's intentions on Tuesday, saying Pakistan "needs his leadership".
"There is no doubt that he will remain a candidate for the post of president after 2007 and, Inshallah, he will win," he told Reuters.
Under the constitution, Pakistan is due to hold parliamentary elections in 2007. The president is then due to be selected by an electoral college made up of parliament and the assemblies of Pakistan's four provinces.
At present the Pakistan Muslim League, which supports President Musharraf, holds a majority in parliament and three of the provincial assemblies.
The government has been holding talks with the main secular opposition parties, led by Mr Sharif and Ms Bhutto, both of whom live outside Pakistan.
Both the secular and Islamic opposition parties have been at odds with Gen Musharraf since 1999, and were enraged when he went back on his promise to stand down as head of the military.
However, he has enjoyed strong support from the West, particularly the US since the 11 September, 2001, attacks.