ISLAMABAD, Pakistan — A former prime minister, Nawaz Sharif, began a last-ditch effort yesterday to persuade fellow opposition leader, Benazir Bhutto, to join a boycott of parliamentary elections — but he suggested his party was ready to contest the vote if he fails.

It was the first meeting between the two former premiers since they both returned from exile in recent weeks. The talks came hours after an election official rejected Mr. Sharif’s own candidacy for the January 8 vote, a decision that could deprive him of the chance to become prime minister for a third time.

Ms. Bhutto reiterated that she thought all opposition parties should take part in the vote, despite concerns it won’t be free and fair, rather than leave the field open to supporters of President Musharraf. Opposition parties, enraged by Mr. Musharraf’s imposition of a state of emergency a month ago, complain that the judiciary and election authorities are biased in favor of the president’s supporters.

Mr. Musharraf and the American administration are urging them to abandon the threatened boycott, fearing it could derail hopes for a smooth transition to democracy and a moderate government committed to fighting Islamic extremism.

Javed Hashmi, a senior official in Mr. Sharif’s party, said they were still consulting with other opposition groups in search of a collective decision for a boycott, but he added it was likely they would decide to take part if Ms. Bhutto and other leaders disagreed. “We’re not sure until a final decision is taken, but it seems difficult not to contest the elections,” he said.

Speaking before the meeting with Ms. Bhutto, Mr. Sharif dropped a strong hint that he was preparing to let his party fight the elections, although an election official for the constituency in the eastern city of Lahore that he hopes to contest upheld complaints filed against his candidacy. Mr. Sharif said he would tell an alliance of Mr. Musharraf’s most vociferous opponents, which he leads, that “we should now be fighting these elections, we should be fighting dictatorship with more vigor and determination.” However, several party leaders said shunning the poll was still the goal.

A ruling party candidate for the National Assembly seat that Mr. Sharif is listed to contest had complained that the former prime minister was ineligible because of a conviction on charges related to the 1999 coup in which Mr. Musharraf ousted his government.

He also complained about Mr. Sharif’s alleged default on a bank loan and an incident in 1997 in which Mr. Sharif’s supporters stormed the Supreme Court.

An election official, Raja Qamaruz Zaman, said the objections had been “accepted” but provided no details.

Mr. Sharif said he had yet to decide whether to appeal the ruling, but he added that to do so would be tantamount to recognizing courts purged of independent-minded judges under the emergency.

“These judges don’t owe their allegiance to the state but to Mr. Musharraf,” he told reporters after meeting the visiting Turkish president, Abdullah Gul.

Earlier yesterday in Lahore, Mr. Sharif met with an American ambassador, Anne Patterson, who urged all opposition parties to take part in the elections. She reiterated America’s calls for lifting curbs on the press and freeing all detainees.

But she refrained from calling for the reinstatement of the Supreme Court justices, a key opposition demand that Mr. Musharraf has repeatedly rejected. The judges had been apparently set to rule him ineligible for another term as president. Mr. Sharif later arrived in the capital where about 3,000 people, many of them chanting “Prime Minister Nawaz Sharif,” gathered at the airport to welcome him.

Mr. Musharraf retired as army chief and took the oath as a civilian president last week.