Uber offers free rides for Turkey referendum day

Taxi hailing app Uber has said it will offer free rides in Istanbul on Sunday, when Turkey is set to hold a hotly contested national referendum that could turn the country's political system into a presidential one.

The move comes amid competition pressure on the company from rivals, including homegrown app Bitaksi.

"Uber will take everyone to the ballot boxes for free in the referendum being held on April 16," the company said in a statement.

Turkey will vote on whether President Recep Tayyip Erdogan should be granted sweeping powers that will bring about one of the most drastic changes to the country's governing system since the republic was established almost a century ago.

Erdogan, whose critics say has increased authoritarian powers since July's failed putsch, claims the reforms are needed to strengthen the country. 

The latest polls show a close race, with the "yes" vote in support of changes to Turkey's parliamentary system currently holding a small lead.

If passed, Turkey's president will be able to issue decrees, declare emergency rule, and appoint ministers and top state officials.

A vote in favour of the reforms could result in Erdogan remaining in power until 2029.

Ahead of Sunday's vote, hundreds of thousands of Turkish expats have already cast their ballots, according to data collected by President Erdogan's AKP Party.

Around 697,000 Turks went to the polls in Germany between March 27 and April 9, marking an eight point increase on the turnout for Turkey's November 2015 elections.

Voter turnout in France, the Netherlands and Austria had also reportedly increased.