The Supreme Court says it will weigh in Monday on Pakistan political turmoil.

Hours after Prime Minister Imran Khan declared the National Assembly dissolved on Sunday, preventing a no-confidence vote that seemed sure to oust him, opposition leaders challenged the move before Pakistan’s Supreme Court.

The Supreme Court said it would hear their petition Monday. The court could declare Mr. Khan’s move unlawful and allow the vote to proceed.

Should that happen, it is far from clear what Mr. Khan would do next.

Some analysts in Pakistan speculated that he might have members of the opposition arrested, on the grounds that they were part of what he claims to be an American conspiracy to remove him from office. Mr. Khan has led a growing crackdown on dissent, and opponents have accused him of targeting opposition members under the pretext of an anticorruption campaign.

One lawmaker from Mr. Khan’s Tehreek-e-Insaf party, Kanwal Shauzab, said arresting opposition members was a “possibility” as long as it was done “in accordance with the law of the land.”

“We are not going to go after the opposition without any reason. It’s what they have done. They have to pay for their own deeds,” she added.

Such arrests could reduce the majority that had seemed poised to oust Mr. Khan. But his move Sunday seemed to risk costing him supporters of his own. One outspoken lawmaker from his party, Aamir Liaquat Husain, resigned in protest, joining dozens of members of Mr. Khan’s coalition who have defected in recent weeks.

Trying to head off such defections, the interior minister said Tehreek-e-Insaf had the support of Pakistan’s institutions in dissolving the legislature — an apparent reference to the military, whose backing is considered critical to the survival of Pakistan’s civilian governments.

Military leaders had appeared to withdraw support from Mr. Khan late last year after a dispute over its leadership. They have maintained that the military remains neutral in the current political crisis.

But a spokesman for the army denied that it had been involved in or supported Sunday’s developments. It was the first time military leaders had so openly suggested that they did not support Mr. Khan’s bid to stay in office. To some, it raised the possibility of military intervention — a familiar pattern in Pakistan’s history — should the political crisis drag on.