"April 16 will be a historic milestone," Recep Tayyip Erdogan told a massive rally at the central Gundogdu Square in Turkey’s third-largest province, following a similar mega-rally in Istanbul Saturday.
"Izmir, let all of Europe -- not only the Aegean region -- hear your answer," he said, asking the crowds:
"Will you say yes on April 16 for a great, strong, prosperous, and stabilized Turkey?"
The crowd enthusiastically shouted "Yes!"
‘Young people in parliament’
The president also rejected claims by the main opposition Republican People's Party (CHP), which has argued against the changes.
He denied the party's claim that the changes would leave the country under one-man rule, adding that party leader Kemal Kilicdaroglu should "look back at the CHP's own history."
On another change which would see the minimum age for parliamentary candidates lowered to 18, the president also rebuffed claims that those young deputies would be exempted from compulsory military service.
"Serving in the army is of course sacred [...] But serving as a deputy is also not something ordinary," he said, adding they would find a way to deal with the issue.
"Our young people will take their place in parliament."
Erdogan claimed that Izmir -- a traditional CHP stronghold -- "will ruin the plans” of the CHP in next Sunday’s referendum.
He encouraged the people of Izmir to cast a "record number of Yes votes."
‘The republic is ours’
Also addressing the rally, Prime Minister Binali Yildirim stressed unity, saying that the country cannot be divided over how it votes in the referendum.
"We victoriously concluded the War of Independence together, we founded the republic together, this victory is ours, the republic is ours," Yildirim said.
He added that since the Justice and Development (AK) Party came to power in 2002, winning 363 out of 550 seats in parliament and forming a government without needing a coalition partner, they have never interfered with anyone's language, culture, ideology, or faith.
Next Sunday, Turkish voters will be asked to vote Yes or No to an 18-article constitutional reform bill which would shift the country from a parliamentary system of governance to a presidential one.
The Yes campaign is backed by the ruling AK Party and opposition Nationalist Movement Party (MHP), while the CHP has argued against the changes.