Many polling stations were nearly deserted Wednesday on the third day of voting in Egypt’s presidential election, highlighting front-runner Abdel Fatah al-Sissi’s lack of a formalized political base and threatening the overwhelming mandate sought by his campaign.

With turnout figures from Egypt’s election commission unavailable, it remains unclear how many went to the polls. An election official told state media that participation had reached 37 percent Tuesday, but a local election monitoring group and the campaign of opposition candidate Hamdeen Sabahi said the initial turnout was as low as 15 percent.

It was a dismal showing despite signs that the state machinery tried to boost voter participation. The two-day election, which began Monday, was extended by a day, and banks and state workers were given a public holiday Tuesday.

Sissi, a former defense minister who has enjoyed unprecedented support since he ousted Islamist President Mohamed Morsi last summer, is still widely expected to win the nation’s highest office. Partial results announced Wednesday showed him with 4.2 million votes compared with 133,548 for Sabahi, the Associated Press reported, after votes from 2,000 polling stations were tallied.

But because Sissi’s campaign relied largely on his personal popularity and a disparate group of supporters to mobilize voters, there was no unified electoral machine to grant the former army chief the ballots he needed to claim sweeping success. Sissi refused to even release a formal political platform ahead of the vote.

“What we’re seeing is the manifestations of there not being organized civilian politics in the country,” said Josh Stacher, a professor of Middle East politics at Kent State University.

Some observers here attributed the dearth of voters at the polls to hot weather, political apathy and an election boycott called by the Muslim Brotherhood, which backed Morsi’s presidency and is now the prime target of a Sissi-led crackdown.

But with little campaigning by Sissi, “people feel like they’re not being consulted” about the process, Stacher said Wednesday. “So, in that case, they just won’t go to the polls.”

After the coup against Morsi, Sissi emerged as an admired strongman whom many here saw as the type of leader Egypt needed to end the political and economic turmoil that followed the 2011 uprising against the Hosni Mubarak government.

Government and private media, as well as other state organs, lined up behind him as he spearheaded an oppressive security campaign, first against the Muslim Brotherhood and then against dissidents of all stripes. Supporters plastered Sissi’s image on posters, chocolates, T-shirts and more. In that sense, his campaign unofficially started months ago.

But even supporters acknowledged there was little effort to engage in a coordinated way at the grass-roots level. This is in contrast to the Brotherhood, once the country’s largest and most organized political group. The Brotherhood tapped into its extensive and localized network of charities and social services during the 2012 presidential election, which Morsi won. Its disciplined political rallies targeted members with slick messaging.

“We expected Sissi’s campaign to be organized like us. But we found ourselves hanging posters alone, holding conferences [with voters] alone,” said Sameh Abdel Hamid, a member of the Salafist Nour party in Alexandria. Nour, a former Brotherhood ally, supported Morsi’s overthrow and says it backs Sissi in this election, seeing him as a candidate capable of ending Egypt’s political instability.

“We have millions of followers, but Sissi’s core campaign has just a few individuals,” Abdel Hamid said. “No one could see them on the ground.”

Another constituency Sissi failed to exploit was the voting population linked to the National Democratic Party (NDP), the ruling party under Mubarak. The party was dissolved in the wake of the 2011 revolt, but its former lawmakers maintain influence among tribes and villages across the country — and can still translate that clout into political capital.

“Sissi did not reach out to the NDP,” said Abdel Fattah Ali Hassan, a former NDP lawmaker from Cairo’s hardscrabble Sayeda Zeinab district. “If he had reached out and secured our support, the turnout would have been noticeably higher.”

Sissi may have wanted to steer clear of any connection with the widely reviled Mubarak era. But Stacher said it is likely that Sissi assumed that his wide following on the streets would translate into heavy turnout and that he did not need to court multiple constituencies.

Hisham Kassem, a Cairo-based analyst and former political activist, warned that meager turnout could cripple Sissi early on in his presidency.

“Sissi will definitely start things off with a handicap if turnout is as low as reported,” he said. “It’s much lower than I expected. And if Sissi doesn’t deliver, I have no doubt there will be a third uprising.”

Sharaf al-Hourani contributed to this report.