Former Prime Minister Benazir Bhutto called on supporters Wednesday to defy a ban on protesting Pakistan's imposition of emergency rule "at all costs," even as the government threatened to crush her demonstrations.

She also said more than 400 members of her Pakistan People's Party have been arrested.

Supporters were planning a rally Friday in the nearby city of Rawalpindi, the opposition leader said, and intended to make a 186 mile march from the eastern city of Lahore to the capital of Islamabad early next week.

"I request my brothers and sisters to reach Rawalpindi at all costs," said Bhutto — who survived a suicide bombing on Oct. 18 that killed more than 140 people — setting the stage for a showdown with authorities who vowed to come out in full force.

The mayor of Rawalpindi said police would prevent anyone reaching the park where Bhutto hoped to address supporters on Friday.

"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," mayor Javed Akhlas told The Associated Press, claiming there was a "strong threat" of another suicide attack against Bhutto. He did not elaborate.

Musharraf, who took power in a 1999 coup, suspended the constitution after declaring the state of emergency Saturday. He has since ousted independent-minded judges, put a stranglehold on the media and granted sweeping powers to authorities to crush dissent. Thousands of people have been rounded up and thrown in jail since then.

With the encouragement of the United States, Musharraf had been holding talks with Bhutto that were widely expected to lead to a power-sharing arrangement after parliamentary elections, which were originally slated for January.

Bhutto said Tuesday that Musharraf's resort to authoritarian measures was a "breach of trust" with her and that the talks were off. However, she also suggested that they could resume if circumstances change.

"I think we should all come down as strongly as we can for the restoration of democracy. And if General Musharraf wants to find a way out, well the ball is in his court," she said.

The United States and other foreign donors to Pakistan are pressing loudly for the elections to be held on time. They are also urging Musharraf to keep a promise to quit his post as army chief — the real source of his power.

"For elections to be credible, opposition political party leaders and their party workers must be released from jail or house arrest. The media must be free to report on events and share their opinions with the public," U.S. Ambassador Anne Patterson said after meeting the head of the election commission.

Musharraf says he suspended the constitution because the courts were hampering Pakistan's effort to fight extremism — for instance by ordering the release of suspects held without charge. But opponents accuse him of a mounting a last-ditch maneuver to stay in power.

In an op-ed piece published Wednesday in The New York Times, Bhutto urged the U.S. to tell Musharraf it expects internationally monitored elections to be held within 60 days.

"It is dangerous to stand up to a military dictatorship, but more dangerous not to," Bhutto wrote. "The moment has come for the Western democracies to show us in their actions, and not just in their rhetoric, which side they are on."

Bhutto met with other opposition parties in Islamabad on Wednesday to discuss a joint strategy against the emergency. However, the party of Nawaz Sharif, the premier Musharraf deposed in a coup in 1999, snubbed the gathering.

Bhutto's earlier negotiations with Musharraf meant that she had broken with the rest of the opposition, said Ahsan Iqbal, a spokesman for Sharif's Pakistan Muslim League-N party.

"There was a clear understanding ... but, Benazir Bhutto violated it," Iqbal told the AP.

He challenged Bhutto to make a clear statement that she had severed her ties with the military-led government.

Musharraf purged the Supreme Court just as it was preparing to rule on the legality of his contested re-election as president last month. The court also has pressed for authorities to allow the return of Sharif from exile in Saudi Arabia.

On Wednesday, police pushed back about 80 lawyers who tried to gather near the main court complex in Rawalpindi, said Mohammed Khan Zaman, a member of the local lawyers' association.

In Islamabad, about 200 attorneys held a rally inside the district court, chanting "Go Musharraf, Go" and "No Musharraf, No."

Lawyers particularly are incensed by the ouster of Chief Justice Iftikhar Mohammed Chaudhry, an independent-minded judge whom Musharraf had tried unsuccessfully to fire earlier this year.

Chaudhry is under house arrest in Islamabad but managed on Tuesday to use a cell phone to urge lawyers to take to the streets.

"We should act upon this message and it will be decided once and for all if the army or the people will rule Pakistan," Zaman said.