After a testy campaign that featured strong attacks on the government by virtually all the candidates over the economy, internet restrictions and harsh enforcement of the hijab law on women, Iran will hold elections on Friday to pick a president.

The vote comes at a perilous time for the country, with the incoming president facing a cascade of challenges, including discontent and divisions at home, an ailing economy and a volatile region that has taken Iran to the brink of war twice this year.

With the race coming down to a three-way battle between two conservative candidates and a reformist, many analysts predict that none of them will achieve the necessary 50 percent of the votes, necessitating a runoff on July 5 between the reformist candidate and the leading conservative.

That outcome may be avoided if one of the leading conservative candidates withdraws from the race, but in a bitter public feud, neither Gen. Mohammad Baqer Ghalibaf, a former commander in the Islamic Revolutionary Guards Corps and a pragmatic technocrat, nor Saeed Jalili, a hard-liner, has budged.

The polls open at 8 a.m. Friday local time across the country, with closings typically extending well into the night. But Iranian elections are tightly controlled, with a committee of appointed clerics and jurists vetting all the candidates and the intimidation of opposition voices in the news media. As a result, many Iranians are expected to sit out the vote, either as a protest or because they do not believe that meaningful change can come through the ballot box.