ISLAMABAD (REUTERS) - Pakistan's top court hopes to wrap up on Thursday (April 7) a hearing on Prime Minister Imran Khan's obstruction of an opposition bid to oust him, a manoeuvre his critics say was unconstitutional and has led to political turmoil in the nuclear-armed country.

Former cricket star Khan lost his parliamentary majority last week and was on the verge of being forced from office by a no-confidence vote tabled by the opposition on Sunday.

But the deputy speaker of parliament, a member of Mr Khan's party, threw out the motion, ruling it was part of a foreign conspiracy and unconstitutional. Mr Khan then dissolved parliament.

The stand-off has thrown the country of 220 million people, ruled by the military for extended periods since independence in 1947, into a full-blown constitutional crisis.

The opposition has challenged the decision to block the vote in the Supreme Court, which began deliberating the case on Monday. The court is due to reconvene on Thursday for a fourth day at 9.30am (12.30pm Singapore time).

Chief Justice Umar Ata Bandial said on Wednesday he wanted to wrap up the hearing.

"Let's start early from tomorrow to conclude the case," he said at the end of a session in which defence lawyers offered a justification for Mr Khan's actions.

 Pakistan’s election commission said on Thursday it cannot hold snap polls within 90 days, as requested by the president, and the earliest it could do so was October.

The president had asked the election commission to propose a date within the next 90 days to hold snap polls after PM Khan dissolved the lower house of parliament on Sunday.

“The Election Commission though fully committed to hold elections would however require at least four additional months,” the commission’s statement said, citing the need to update constituency boundaries and other issues.

On the move to oust Mr Khan, his supporters have argued that the opposition bid to oust him with foreign support was unconstitutional. Opposition leaders have rejected that.

The court could order parliament to be reconstituted, call for new elections or bar Mr Khan from power if he is found to have violated the constitution.

It could also decide that it cannot intervene in parliamentary affairs.

The military has stepped in to overthrow civilian governments and rule the country on three occasions citing the need to restore order. It has denied any involvement in the current crisis.