Former Pakistani Prime Minister Benazir Bhutto has issued what correspondents say is an ultimatum to President Pervez Musharraf to end emergency rule.
Benazir Bhutto wants elections to be held on schedule
She repeated plans for a rally on Friday, despite an official ban, and called for a "long march" next week unless Gen Musharraf changed course.
She insisted that he restore the constitution, hold elections and resign as head of the army.
Gen Musharraf imposed emergency rule on Saturday after months of unrest.
The authorities have warned that police will not allow Friday's demonstration in Rawalpindi, the country's main garrison town, to go ahead.
The city's mayor, Javed Akhlas, said: "We will ensure that they don't violate the ban on rallies, and if they do it, the government will take action according to the law."
He told the Associated Press there was a "strong threat" of another suicide bomb attack against Ms Bhutto, who survived an assassination attempt in Karachi on 18 October that killed more than 140 people.
"I appeal to the people of Pakistan to come forward. We are under attack," Ms Bhutto told journalists.
Protests have so far been populated mainly by lawyers
She said if the security forces made it impossible to hold the rally in Rawalpindi it could be held in the eastern city of Lahore.
She also called for a "long march" starting next Tuesday, 13 November, from Lahore to Islamabad, if her key demands were not met.
- For the state of emergency to be called off, and the constitution restored
- For General Musharraf to stand down as head of the army
- For elections to be held by mid-January
- For the release of all lawyers, judges and activists arrested in the last few days
"How many people can they put behind bars? We will produce so many that they will not have enough jails," she said.
After her news conference police used teargas against a small number of her supporters in Islamabad.
Until now, protests across the country have been limited in scale, with Ms Bhutto refraining from urging supporters of her Pakistan People's Party (PPP) - the country's leading political group - onto the streets.
But correspondents say a huge popular rally could raise the stakes dramatically in the country's political crisis.
Emergency 'to end'
Ms Bhutto was speaking after meeting other opposition groups in Islamabad - though some significant players were missing.
The important MMA (United Council of Action) - an alliance of Islamic parties - and the PML-N party of former Prime Minister Nawaz Sharif were not there.
Nor was the Movement for Justice Party of former cricket star Imran Khan.
Mr Khan was one of several leading politicians to be put under house arrest following the decree, which the government issued on Saturday, for what it said were reasons of national security.
However Mr Khan slipped his guards and on Wednesday issued an appeal by video from a secret location.
He said he wanted to galvanise all parts of society towards "massive street protests".
"I think that if we do not resist this, if we do not raise our voices against this, if we do not struggle against this, he will take the country towards destruction," he said.
However, a top official from President Musharraf's ruling party said emergency measures might soon come to an end anyway.
Chaudhry Shujaat Hussain, president of the ruling Pakistan Muslim League, told the Dawn newspaper: "I'm sure it will end in two to three weeks as President Pervez Musharraf is aware of the consequences of long emergency rule."
But there appears to be a split between those members of the party advocating that parliamentary elections should be held on schedule in January, and those who want them postponed, says the BBC's Barbara Plett in the capital, Islamabad.