TEHRAN, Iran — Iran’s interior minister says preliminary election returns give reformist-backed candidate Hasan Rowhani a significant lead in the presidential race.

The minister, Mostafa Mohammad Najjar, said Saturday on state television that Rowhani has nearly 402,000 votes out of a total of 861,866 counted.

That gives the former nuclear negotiator an early wide margin over Tehran Mayor Mohammad Bagher Qalibaf, with about 126,000 votes, and nuclear negotiator Saeed Jalili, with about 119,000.

Reform-minded Iranians who have faced years of crackdowns looked Friday to claw back a bit of ground in a presidential election that gave them an unexpected hero and a chance to upend a vote that once appeared solidly in the hands of Tehran’s ruling clerics.

While Iran’s presidential elections offer a window into the political pecking orders and security grip inside the country — particularly since the chaos from a disputed outcome in 2009 — they lack the drama of truly high stakes as the country’s ruling clerics and their military guardians remain the powers.

Election officials began the ballot count after voters waited in line for hours in wilting heat at some polling stations in downtown Tehran and other cities, while others cast ballots across the vast country from desert outposts to Gulf seaports and nomad pastures. Voting was extended by five hours to meet demand, but also as possible political stagecraft to showcase the participation.

The apparent strong turnout suggested liberals and others abandoned a planned boycott as the election was transformed into a showdown across the Islamic Republic’s political divide.

A preliminary sampling of results from around Iran suggested Rowhani’s appeal was broad in cities and rural areas, although the tally was too small to draw clear trends, officials handling the ballot count told The Associated Press. They spoke on condition of anonymity because they were not authorized to brief media.

But even if the last-moment surge around Rowhani brings him to the presidency, it would be more of a limited victory than a deep shake-up.

Iran’s establishment still holds all the effective power and sets the agenda on all major decisions such as Iran’s nuclear program and its dealings with the West.