Pakistan Peoples Party (PPP) chairperson Bilawal Bhutto Zardari on Thursday said Interior Minister Chaudhry Nisar Ali Khan has failed in his plan to become prime minister of the country.

“Chaudhry Nisar’s campaign to become PM is not going as well as planned and he is getting frustrated,” Bilawal said in a message posted on micro-blogging website Twitter.

The PPP chairman further said it was inappropriate to take advantage of Prime Minister Nawaz Sharif’s illness in such a way. “Poor form taking advantage of PM’s illness like this.”

‘Absence’ of Nawaz Sharif leaves PML-N in the lurch

Bilawal’s remarks coincided with PM Nawaz’s successful open heart surgery in London where he is likely to remain hospitalised for a whole week after the procedure. The premier has travelled to London for medical treatment several times over the past year and was accompanied on this trip by his brother, Shahbaz Sharif, who is chief minister of Punjab, and several other family members.

PM Nawaz’s surgery comes as his government prepares to present its annual budget on Friday. It also remains under pressure over allegations of corruption linked to the so-called Panama Papers.

Nawaz, 66, was prime minister for two terms in the 1990s before being overthrown in a 1999 military coup. After years in exile, he returned to Pakistan in 2007 and led his party to a victory in a 2013 election.

Earlier, sources said either Finance Minister Ishaq Dar or Nisar will look after government affairs in PM’s absence. Experts said an acting prime minister cannot be appointed as the Constitution does not give any provision for that.

PM undergoes successful open heart surgery

The federal cabinet will carry on the government affairs collectively as the Article 90 Section 2 of the Constitution says the PM is entitled to exercise his power directly or through a federal minister. The federal minister, appointed by him, can chair the federal cabinet’s meetings. However, if the prime minister’s illness protracts then the federal budget for 1016-17 may get delayed.