Vladimir Putin has moved to cement his hold on power in Russia beyond the middle of the decade, backing a proposed constitutional amendment that would allow him to seek another two terms in the Kremlin.

The Russian president is required by the constitution to step down in 2024, and there have been months of conjecture about how he could stay in power beyond then, or at least ensure a safe transition for himself.

In the end, the puzzle was resolved in an afternoon, in a series of choreographed political steps that took just over three hours and could result in Putin staying on as president until 2036.

The venture began in parliament, where a member of Russia’s ruling party proposed amending the constitution in a way that would “reset” Putin’s presidential term count back to zero.

Putin then announced he would come to address the parliament himself, prompting breathless coverage on state television about whether he would accept or turn down the proposal.

“In principle, this option would be possible,” he said at the end of a half-hour speech. “But on one condition – if the constitutional court gives an official ruling that such an amendment would not contradict the principles and main provisions of the constitution.”

He also said the move would have to be approved by the public in a referendum next month.

It was a significant, if not surprising, about-face for the president, who has been signalling publicly in recent months that he could leave the presidency. In January, he told a veteran of the second world war that he was worried about a return to the 80s, when Kremlin leaders “stayed in power until the end of their days” and did not provide for a transition of power.

On Tuesday, he walked back that statement, saying that modern Russia’s elections made it impossible to return to a Soviet-style procession of leaders-for-life. “I won’t hide that I was wrong,” he said. “It was an incorrect statement because during the Soviet Union there were no elections.”

Timeline Putin's hold over power in Russia Show Hide Acting prime minister Boris Yeltsin sacks his cabinet and appoints Putin, a political neophyte who headed the main successor to the KGB, as his acting prime minister and heir apparent. Acting president Yeltsin stuns Russia and the world by using his traditional new year message to announce his resignation and hand his sweeping powers, including the nuclear suitcase, to Putin. President (first term) Putin wins a surprisingly narrow majority in his first presidential election, taking 53% of the vote and avoiding a second round run-off. President (second term) Putin consolidates his centralised control of power by cruising to a second term as president with 71% of the vote, having limited press access to his opponents and harassing their campaigns. Prime minister Putin is prevented by the constitution from running for a third term as president. The First deputy prime minister Dmitry Medvedev is elected in his stead. One of his earliest moves is to appoint Putin as prime minister, leaving little doubt that the two men plan, at the very least, to run Russia in tandem. President (third term) Amid widespread allegations of vote-rigging, Putin returns to the role of president, taking 63.6%. Medvedev becomes his prime minister. "Putin has named himself the emperor of Russia for the next 12 years," says protest leader Alexei Navalny. President (fourth term) Putin is re-elected until 2024 with 77% of the vote, amid high tensions between London and Moscow over the Salisbury nerve agent attack. Opposition activists highlight a number of cases of vote-rigging and statistical anomalies. Russia holds a yes/no referendum on various topics including a proposal to amend the constitution to allow Putin to seek another two terms in the Kremlin. The resolution passes, potentially allowing him to rule as president until 2036.

Ironically, the amendment piggybacks on plans to change the constitution to prevent anyone from serving more than two terms as president in total. The amendment says that the new rule would not count any presidential terms already served. In reality, the amendment affects only two living Russians, Putin and the former prime minister Dmitry Medvedev.

Russia’s opposition, including Putin’s most prominent critic, Alexei Navalny, denounced the proposals as an effort to make him “president for life”. “Interesting how things turn out,” Navalny said in a tweet after Putin’s speech.

Supporters of Putin said the amendment would prevent instability and avoid his being made a lame duck in his last term. “No one is saying that the amendments being proposed today are for Vladimir Putin,” said Alexander Khinshtein, a member of the ruling United Russia party, on state television. He also noted that Putin had not said he would necessarily run in 2024. “But the head of state should have that ability to maintain stability in society.”

Valentina Tereshkova, an MP who as a Soviet cosmonaut became the first woman to fly to space, proposed the amendment as part of a series of constitutional changes going to a nationwide vote on 22 April.

While addressing the Duma on Tuesday, Tereshkova said: “The very existence of an opportunity for the current president [to be re-elected], given his major gravitas, would be a stabilising factor for our society.”

With Putin’s backing, there is little doubt the measure will pass. Support from the constitutional court is likely to be a rubber stamp. Less than an hour after Putin’s address to lawmakers, parliament approved the amendment as part of a wider revision of Russia’s constitution.

The 67-year-old, in power for 20 years, is Russia’s longest-serving leader since Stalin. If he serves out both terms from 2024 he will surpass the Soviet dictator.

The decision comes after a months-long effort to revise Russia’s constitution announced in January by Putin. Before Tuesday, some observers believed he was seeking another seat in government to maintain power and ensure his personal safety after leaving the presidency.

It is unclear whether Putin had planned to stay on as president all along or had come to the decision more recently.

In his speech, he said he hoped that one day the institution of the presidency in Russia would not be “so personified in a single person”, but added: “that is how all of our history ended up and of course we can’t not take that into account”.

On the subject of whether he would actually run again in 2024, Putin told lawmakers: “I’m sure that we will do many great things together, at least before 2024. Then we’ll see.”