By Ece Toksabay
ISTANBUL (Reuters) - Activists behind last summer's anti-government demonstrations in Turkey called on Tuesday for a mass protest this weekend to mark the first anniversary of the unrest, raising the prospect of renewed clashes with the police.
What began as a peaceful demonstration against plans to redevelop Gezi Park, a leafy corner of central Istanbul's Taksim Square, spiraled into nationwide protests against Prime Minister Tayyip Erdogan a year ago after a police crackdown.
Taksim Solidarity, a collective of labor unions, opposition parties and civil society groups which helped organize the protests, said it would take to the streets again on May 31st to mark the anniversary of the start of the unrest.
"We will be on the streets, with millions of people, with tens of different languages, different voices and all of our colors," it said in a statement.
It is unclear how widely followed the call will be. Riot police have maintained a presence on Taksim since last year and on May 1 prevented labor unions from getting anywhere near the square, a traditional rallying point for May Day marches.
Erdogan has also reasserted his authority since last year's troubles, with his ruling AK Party sweeping to victory in municipal polls at the end of March, including in Istanbul and the capital Ankara, leaving the opposition smarting.
Mucella Yapici, a spokeswoman for Taksim Solidarity, said the group aimed to make clear that it had not dropped its demands, including the dismissal of charges against those involved in the protests.
Those demands look unlikely to be met. A Turkish court on Tuesday issued arrest warrants for 47 of 255 suspects in an ongoing case over the unrest.
"The government is pushing a climate of tension with policies encouraging police violence," Yapici said, pointing to the heavy police presence on May Day, a clampdown on protests after this month's mine disaster in the western town of Soma, and violence following a funeral for a protester who died after almost a year in a coma.
According to police records, more than 3 million people across Turkey, which has a population of 77 million, attended last summer's protests.
(Editing by Nick Tattersall and Angus MacSwan)