Senate Chairman Sadiq Sanjrani on Saturday appointed PML-N's Raja Zafarul Haq leader of the opposition in the Upper House, according to a notification issued by the Senate Secretariat.

Haq replaced PPP Senator Sherry Rehman with effect from Aug 24, according to the notification. Haq, who previously served as leader of the house, was replaced by Pakistan Tehreek-i-Insaf Senator Shibli Faraz on Aug 24.

Haq had been a contender for the election of Senate chairman against Sadiq Sanjrani earlier this year but lost by 11 votes.

Read more: PML-N seeks to change opposition leader in Senate

Rehman tweeted her congratulations to both Faraz and Haq on Sunday. "I hope they both remember the best service to democracy lies in serving public interests via legislation, debate, good governance and parliamentary probity."

The PML-N sought to replace Rehman days after the election for prime minister in the National Assembly. The PPP had withdrawn its support for PML-N President Shahbaz Sharif during the election, abstaining from voting ─ a move that caused a rift in the opposition parties' alliance.

The PPP and PML-N are currently embroiled in a tussle over nominating a suitable candidate for the post of president. The PPP had earlier nominated Aitzaz Ahsan as its candidate and attempted to convince other opposition parties in the 11-party Pakistan Alliance for Free and Fair Elections to support him.

Read more: 'PML-N may consider Aitzaz Ahsan for president if he apologises to Nawaz Sharif'

The opposition parties at a meeting in Murree yesterday had rejected Ahsan as a candidate, but said they were ready to back a candidate other than him.

The alliance is set to announce its presidential candidate today. The nominee will be in the running for the post against PTI's Arif Alvi.

Haq calls his first meeting as opposition leader

Haq, after assuming the role of the opposition leader in the Senate, has called the first meeting between PML-N's parliamentary party and the alliance on Monday.

During the meeting, the course of action to be taken by the opposition in the Senate will be charted out.

"Discussions will be held on how to give the Tehreek-i-Insaf government a tough time in the Senate," said a source within the PML-N.

With additional reporting by Javed Hussain.