What Happens Next in Pakistan’s Politics?

Imran Khan’s stunning performance in Pakistan’s national election has upended most traditional political forecasts in a country where leaders who run afoul of the powerful military rarely find electoral success.

Supporters of Mr. Khan, the jailed former prime minister, are both electrified by the showing of candidates aligned with his party, who won the most seats in last week’s vote, and enraged by what they call blatant rigging and the possibility that other parties will ultimately lead the government.

Here’s what to know about the uncertainty now hanging over Pakistan’s political system.

What’s next for the government?

Mr. Khan’s supporters are challenging the results of dozens of races in the country’s courts, and pressure is growing on Pakistan’s Election Commission to acknowledge the widely reported irregularities in the vote counting.

Backers of Mr. Khan say they will hold peaceful protests outside election commission offices in constituencies where they contend the rigging took place. Protests have already erupted in several parts of the country, especially in the restive southwestern Baluchistan Province.

As of midday Sunday, the Election Commission had not finalized the results from Thursday’s vote. Preliminary counts showed victories for 92 independents (primarily supporters of Mr. Khan, whose party was barred from running), with 77 seats going to the Pakistan Muslim League-Nawaz, the party of former Prime Minister Nawaz Sharif, and 54 going to the third major party, the Pakistan People’s Party, or P.P.P.