What began last year as small campaign to save Istanbul's Gezi Park from redevelopment eventually drew an estimated three million protesters in an outpouring of anger at the perceived authoritarian tendencies of Erdogan's Islamist-rooted government.
Eight people died and thousands were injured in the heavy-handed police crackdown that ensued, as clouds of tear gas wafted through the much-loved park on Taksim Square.
Despite a ban on protests at the square, the epicentre of last year's demonstrations, activists are calling for a new rally there, raising the prospect of clashes after police confronted protesters trying to defy a similar ban on May Day.
Some 25,000 police officers as well as dozens of water cannon trucks and armoured vehicles were due to be deployed across Istanbul today to prevent demonstrators from reaching the square.
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"We know what happened in June last year and it is not a good memory," Istanbul governor Huseyi Avni Mutlu said this week. "We do not want to see such sorrow again."
The prime minister also urged young Turks to stay away.
"One year later, people, including so-called artists, are calling for demonstrations, but you, Turkey's youth, you will not respond to the call," Erdogan told a crowd of a thousand young people in Istanbul yesterday.