The third of Pakistan's four provinces has called for President Pervez Musharraf to seek a confidence vote from parliament or face impeachment.
Lawmakers in Pakistan's Sindh province chanted "Go, Musharraf, go" Wednesday, as 93 of the assembly's 166 members voted in favor of the motion.
No one voted against the resolution, but about one-third of the lawmakers, including the entire MQM party (Mutahida Quami Movement), abstained from voting.
Opposition leader Jam Madad Ali said the measure was unconstitutional.
Lawmakers from North West Frontier Province passed a similar resolution on Tuesday, while the assembly in Punjab did so on Monday.
The Pakistani constitution does not require Mr. Musharraf to take a vote of confidence, and his spokesman said the president will not step down.
Ruling party lawmakers in Pakistan's National Assembly are drafting a list of impeachment charges to be leveled against the embattled president.
Removing the president requires a two-thirds majority vote in both houses of Pakistan's parliament.
Mr. Musharraf's political opponents say they have the necessary parliamentary backing to unseat the president. But his allies have repeatedly said they do not believe such support exists.
The former army chief seized power in a bloodless 1999 military coup. He ruled largely unchallenged for years while enjoying U.S. support as a close ally in the fight against terrorism.
Some information for this report was provided by AP.