Turkey's prime minister Binali Yildirim called on the opposition to respect the result of a referendum that will give sweeping new powers to the office of President Recep Tayyip Erdoğan on Tuesday (18 April).

Yildirim made the call during an address to legislators from his ruling party, as the country's main opposition prepared to apply to the country's highest electoral board to seek an annulation of Sunday's (16 April) vote, giving President Recep Tayyip Erdogan's "yes" campaign a narrow win, with preliminary results showing at 51.4 per cent in his favour.

The Republican People's Party, or CHP, called for the vote to be annulled citing a series of irregularities, particularly an electoral board decision to accept ballots that didn't bear official stamps, as required by Turkish law. Monitors from the Organisation for Security and Cooperation in Europe, who also listed numerous irregularities, said the move undermined important election safeguards, drawing a harsh rebuke from Erdogan.

Turkey referendum
18 April 2017: Turkey's main opposition leader, the Republican People's Party (CHP) Kemal Kilicdaroglu, arrives at a meeting at the Turkish parliament in Ankara Umit Bektas/Reuters

"Efforts to cast a shadow on the result of the vote by spreading rumours of fraud are futile and in vain," Yildirim said. "The will of the people was freely reflected into the ballot boxes and this business is over. Everyone and all sections – and the main opposition party in particular – must show respect. It is wrong to speak after the people have spoken."

The vote allows Erdogan, who has ruled Turkey first as prime minister and now as president since 2003, to fulfill his long-held ambition for a presidency with executive powers.

The referendum approves 18 constitutional amendments that allow the president to appoint ministers, senior government officials and to hold sway over who sits in Turkey's highest judicial body, as well as to issue decrees and declare states of emergency. The new system takes effect at the next election, currently slated for November 2019. Other changes are to be implemented sooner, including scrapping a requirement that the president not be a member of any political party. This would allow Erdogan to rejoin the governing AK Party he co-founded, or to lead it. Yildirim said on Tuesday that Erdogan would be invited to join the party as soon as the official results are declared. "We will invite our founding chairman to our party and we will feel a huge elation to see him among us," he told the Associated Press.

Hundreds of protesters took to the streets of Istanbul on Monday (17 April) to denounce the referendum results. People marched in the Besiktas neighbourhood with some chanting "It's not over" and "The struggle will continue". The result of the referendum has laid bare the deep divide between the urban middle classes, who see their future as part of a European mainstream, and the pious rural poor who favour Erdogan's strong hand.