Islamabad, April 13 (IANS): Pakistan Prime Minister Nawaz Sharif's visit to Britain on Wednesday -- ostensibly to undergo a pending medical check-up -- has set political circles abuzz after he landed in controversy following the Panama Papers leak.

Sharif will head to London for a three-day visit for a medical check-up, the prime minister's office said on Tuesday.

Only close family members will join Sharif. His two sons -- Hassan and Hussain -- are already abroad, a senior official said.

At a time when Pakistan Tehreek-e-Insaaf chairman Imran Khan is ready to launch a sit-in at Raiwind -- home to Sharif's palatial residence, leaders of the opposition in the senate had been casting doubt on the reason for the prime minister's sudden visit to London.

The movements of Pakistan Peoples Party co-chairperson Asif Ali Zardari, who is also in London, is being closely monitored by the media.

PPP senator Aitzaz Ahsan on Tuesday said: "Sharif has no medical issues and is only visiting London to present himself in the court of Zardari."

Whenever Sharif came under pressure, he always looked towards the PPP leadership for help, Ahsan said.

A senior PTI leader said it was very likely for Sharif to ask the PPP to bail him out, considering the pressure mounting on him for the investigation of his family regarding the leaks.

A Pakistan Muslim League-Nawaz lawmaker admitted that there was a great deal of nervousness among the party's top leaders following the revelation of documents in the Panama Papers leak.