Both "Yes" and "No" camps have just one day to convince any undecided voters in Turkey who will vote in the referendum.
Turkish citizens will cast their ballots on whether to change from a parliamentary to a presidential system of government.
Saturday is the last day for campaigning. On Sunday Turkey's 55 million voters will choose how they want their country to be governed.
The last few weeks saw active campaigning from both the proponents of the constitutional changes and those who are against the proposed reforms.
TRT World's Hasan Abdullah reports on campaigning in Ankara.
Izmir is Turkey's third largest city and is a stronghold of the country's main opposition party, the Republican People's Party (CHP).
The city is expected to vote "No" to the constitutional reforms proposed by the governing Justice and Development Party (AK Party) and also backed by the National Movement Party (MHP).
TRT World's Andrew Hopkins reports from Izmir.