Russians overwhelmingly approved a package of constitutional changes in a nationwide vote, partial results showed Wednesday, allowing President Vladimir Putin to potentially extend his two-decade rule until 2036. With just over 85 percent of ballots counted after the end of seven days of voting, 77.8 percent of voters had supported the reforms, according to election commission figures cited by Russian state agencies. There had been little doubt of voters backing the changes, which Putin announced earlier this year and critics denounced as a manoeuvre to allow him to stay in the Kremlin for life. But top Kremlin critic Alexei Navalny slammed the results as a "huge lie" that did not reflect real public opinion. The amendments had been passed weeks ago by Russia's parliament and copies of the new constitution were already on sale in bookshops, but Putin had said voter approval was essential to give them legitimacy. The reforms include conservative and populist measures -- like guaranteed minimum pensions and an effective ban on gay marriage -- but crucially for Putin also reset presidential limits allowing him to run twice again after his current six-year term expires in 2024. Turnout as of 2000 GMT was about 65 percent, the election commission said. The Kremlin pulled out all the stops to encourage voting, with polls extended over nearly a week, the last day of voting declared a national holiday and prizes -- including apartments, cars and cash -- on offer to voters. Initially planned for April 22, the referendum was postponed by the coronavirus pandemic but rescheduled after Putin said the epidemic had peaked and officials began reporting lower numbers of new cases. - 'Stability, security, prosperity' - In a final appeal to voters on Tuesday, Putin said the changes were needed to ensure Russia's future "stability, security, prosperity". State television showed Putin voting Wednesday at his usual polling station at the Russian Academy of Sciences, where he was handed a ballot by an electoral worker wearing a surgical mask and gloves. Dressed in a dark suit and tie, Putin was not wearing any protective gear. At a polling station in Vladivostok in Russia's Far East, 79-year-old Valentina Kungurtseva told AFP she supported the reforms. "For us as pensioners, it's very important that they will increase our pension every year," she said. "As long as we have a good president, life will be good," she said. In the second city, Saint Petersburg, 20-year-old Sergei Goritsvetov said he opposed the reforms but doubted it would make any difference. "I voted against and I hope there will be many of us, but I don't know what it will change," he said. "At least I expressed my opinion." Navalny had said Putin, 67 and in power as president or prime minister since 2000, wants to make himself "president for life" and called for a boycott, calling the vote illegitimate. "We have just watched a show with a planned finale," he wrote on his blog after polls closed. "Putin will not leave himself," Navalny wrote, "not until we begin to come out to the streets by the hundreds of thousands, by millions." The opposition divided and failed to mount a serious campaign, with some voting "no" and others staying home. There were only small protests in central Moscow and Saint-Petersburg Wednesday. - Falling approval ratings - Golos, an independent election monitor, said it had received hundreds of complaints of violations, including people voting more than once and claims employers were putting pressure on staff to cast ballots. Election commission chief Ella Pamfilova denied any problems on Wednesday, saying only a couple of violations were confirmed and they would have no effect on the result. Putin's approval rating has fallen in recent months. It stood at 60 percent in June according to pollster Levada, down 20 points from the months after his re-election in 2018. Analysts say Putin wanted to get the vote over with before Russians -- already suffering from several years of falling incomes -- are hit by the full economic impact of the pandemic. Putin said in a recent interview that he had not decided whether to run again but suggested that part of the reason for the presidential reset was to allow Russia's political elite to focus on governing instead of "hunting for possible successors".