Turkey’s president has started campaigning for constitutional reforms that would greatly expand the powers of his office, hours after a vote in parliament cleared the way for a national referendum on the issue.

Speaking in Istanbul, President Recep Tayyip Erdogan hailed the assembly’s early-morning decision. “God willing, the people will give the true decision, the final decision” that he said would catapult Turkey to a stronger position.

In an all-night session that ended two weeks of acrimonious debate, the reform bill cleared the minimum threshold necessary for a final approval in a national referendum. A public vote is likely to take place by mid-April, according to ruling Justice and Development Party officials.

The decision marks a victory for Mr Erdogan, a polarising but overall popular figure, who has long advocated a strong presidency that would turn Turkey into a powerhouse.

The ruling party says a presidential system would enable the country to surmount a broad array of internal and external security threats.

Critics fear the changes will concentrate too many powers in the hands of Mr Erdogan, who is accused of authoritarian behaviour and has already established a de-facto presidential system since coming into office in 2014. They say the reforms will erode the few existing checks and balances on government.

In addition to changing the system of government, the reform bill allows the president to keep ties with his party and to restructure the nation’s highest judicial body. It increases the number of seats in the assembly to 600, lowers the minimum age for lawmakers to 18 and foresees simultaneous parliamentary and presidential elections every five years.

In pictures: Turkey coup attempt Show all 17 1 /17 In pictures: Turkey coup attempt In pictures: Turkey coup attempt Turkish President Erdogan attends the funeral service for victims of the thwarted coup in Istanbul at Fatih mosque on July 17, 2016 in Istanbul, Turkey Burak Kara/Getty Images In pictures: Turkey coup attempt Soldiers involved in the coup attempt surrender on Bosphorus bridge with their hands raised in Istanbul on 16 July, 2016 Gokhan Tan/Getty In pictures: Turkey coup attempt A civilian beats a soldier after troops involved in the coup surrendered on the Bosphorus Bridge in Istanbul, Turkey, 16 July, 2016 REUTERS/Murad Sezer In pictures: Turkey coup attempt Surrendered Turkish soldiers who were involved in the coup are beaten by a civilian Reuters In pictures: Turkey coup attempt Soliders involved in the coup attempt surrender on Bosphorus bridge Getty In pictures: Turkey coup attempt Supporters of Turkish President Recep Tayyip Erdogan wave flags as they capture a Turkish Army vehicle Getty In pictures: Turkey coup attempt People pose near a tank after troops involved in the coup surrendered on the Bosphorus Bridge in Istanbul, Turkey, 16 July, 2016 Reuters In pictures: Turkey coup attempt Turkish soldiers block Istanbul's Bosphorus Brigde Getty In pictures: Turkey coup attempt A Turkish military stands guard near the Taksim Square in Istanbul Reuters In pictures: Turkey coup attempt Pierre Crom/Twitter In pictures: Turkey coup attempt Turkish soldiers secure the area as supporters of Recep Tayyip Erdogan protest in Istanbul's Taksim square AP In pictures: Turkey coup attempt People demonstrate in front of the Republic Monument at the Taksim Square in Istanbul Murad Sezer/Reuters In pictures: Turkey coup attempt Turkish soldiers detain police officers during a security shutdown of the Bosphorus Bridge Reuters In pictures: Turkey coup attempt Turkish Army armoured personnel carriers in the main streets of Istanbul Getty In pictures: Turkey coup attempt Chaos reigned in Istanbul as tanks drove through the streets EPA/TOLGA BOZOGLU In pictures: Turkey coup attempt Turkish President Tayyip Erdogan speaks to media in the resort town of Marmaris Reuters In pictures: Turkey coup attempt Supporters of President Erdogan celebrate in Ankara following the suppression of the attempted coup Reuters

Kemal Kilicdaroglu, head of the opposing Republican People’s Party, condemned the outcome in a speech early this morning, saying that parliament had “handed over its own authority” and “betrayed” its history. He vowed to lead a “struggle for democracy” to get the changes rejected in the referendum.

During nearly two weeks of heated debates in the assembly on the topic, MPs traded barbs and came to blows on more than one occasion. Three legislators were hospitalised and two of them returned to parliament to vote in wheelchairs.

The parliamentary vote comes six months after a violent attempt to unseat the Turkish president failed on 15 July and ended with the masses rallying to defend him. Since then, the government has launched a massive crackdown against alleged critics.