PM Imran Khan and other lawmakers attend the National Assembly session in Islamabad. File

Pakistan's parliament will convene on Friday to take up a no-confidence motion against Prime Minister Imran Khan, the lower house (National Assembly) speaker's office said on Sunday, in what is shaping up to be his toughest test since coming to power in 2018.

Speaker Asad Qaiser on Sunday summoned the session of the National Assembly (NA) to deliberate on the no-confidence resolution of the opposition parties against Prime Minister Imran Khan on March 25.

An alliance of opposition parties filed the motion against Imran this month, saying he had lost his parliamentary majority after over a dozen defections from his party, raising the risk of political turmoil in the country.

Under the constitution, the National Assembly (NA) speaker is required to convene the session within 14 days of receiving the motion, which would fall on Monday. But a statement from the NA speaker's office said the date was pushed back several days because of a conference of Islamic countries in Islamabad scheduled for March 23.

The speaker’s notification said the session will convene at 11am on Friday. It was summoned after the joint opposition made the requisition for it under Article 54 of the Constitution along with the submission of the no-trust motion against the prime minister on March 8.

The article says once a session of the National Assembly has been requisitioned with signatures of at least 25 per cent of the members on it, the speaker has a maximum of 14 days to summon the Lower House of Parliament.

Therefore, the speaker had to call the National Assembly in session by March 21. However, the notification explained that on Jan.21 a motion was adopted by the National Assembly to allow the exclusive use of its chamber for the 48th session of the Organisation of Islamic Countries (OIC) Council of Foreign Ministers on March 22 and 23.

Pakistan Peoples Party (PPP) Senator Sherry Rehman condemned the delay and said the speaker could not arbitrarily delay the requisitioned session. "If he violates Article 54, which read with Art 95 of the Constitution of Pakistan, enjoins on him the duty of calling such a session within the outer limit of 14 days, he will invoke Article 6 for violation," she said.

The opposition accuses Imran Khan of mismanaging the economy and foreign policy. He denies this. No Pakistani prime minister has ever completed his full term in office.

PM ready to forgive dissident lawmakers like a compassionate father

Imran appealed to the defected lawmakers to return to the ruling party. "Get back, you will be forgiven," he said at a public rally in northwestern Pakistan. "Like a father forgives his children."

Imran has called on the public to show support for his premiership by holding a "million-man" rally in Islamabad on March 27.

The loss of dissident lawmakers has left Imran about a dozen seats less than the minimum - 172 - needed for a majority. The joint opposition commands 163 seats in the lower house, but could build a majority if most of the defectors effectively join its ranks via a no-confidence vote.

The opposition and political analysts also say Imran has fallen out with Pakistan's powerful military, whose support is critical for any party to attain power in the way the former cricket star's upstart party did four years ago. Imran and the military deny the accusation.