Former Pakistani Prime Minister Nawaz Sharif, convicted in an offshore business scandal last month, arrived in London on Wednesday to go on self-imposed exile, his lawyer said.

Mr. Sharif, 68, a Muslim cleric and longtime political rival of current Prime Minister Imran Khan, has been in a London hospital for treatment of cancer. He could face a lengthy prison sentence when he is sentenced on March 6.

Shortly after leaving the hospital, he boarded a private plane and flew to Dubai, his lawyer said, and then to London, where he is spending the Easter weekend.

Mr. Sharif was convicted and sentenced to 10 years for failing to disclose assets he had concealed while in office, among other crimes, for which he also faces a prison term and additional fines.

Mr. Khan’s current government, meanwhile, is under fire for suspending a chief justice for insulting government opponents in a speech he gave in April.

Mr. Khan, who denies interfering in the justice system, has said that chief justice Saqib Nisar was forced out for criticizing Mr. Khan’s government. He also has called for street protests to force the government to reinstate Mr. Nisar.

In a statement issued by his office, Mr. Khan said that Justice Nisar’s suspension was “retaliation” for his criticism.

The BBC reported Wednesday that Mr. Khan was suspected of having conspired with Mr. Sharif and his brother, Shahbaz Sharif, to suspend the chief justice.

Mr. Khan has denied involvement.

Mr. Khan’s government has ruled out taking Mr. Sharif back into the government to do his jail time. Mr. Sharif has appealed to court to stop Mr. Khan from removing him from office.

Mr. Sharif, a member of the powerful Pakistan Muslim League-Nawaz party, had been Pakistan’s prime minister between 1997 and 1999, when he was forced to step down after a military coup. He also served as leader of Pakistan’s opposition for years before joining the government in 2013.