Result challenged in court

Turkey's opposition yesterday demanded the annulment of a contentious referendum that approved sweeping constitutional changes boosting President Recep Tayyip Erdogan's powers, claiming blatant vote-rigging.

The European Union also urged a probe into the poll fraud claims after international observers voiced concerns, but US President Donald Trump called his Turkish counterpart to offer his congratulations.

Critics fear the changes will lead to autocratic one-man rule under Erdogan, but supporters say they simply put Turkey in line with France and the United States and are needed for efficient government.

The 'Yes' camp won Sunday's poll with just 51.41 percent of the vote but the result has been challenged, with opposition claims of vote rigging and angry protests staged in parts of the biggest city Istanbul.

The main opposition Republican People's Party (CHP) deputy leader Bulent Tezcan formally requested that the Supreme Election Board (YSK) cancel the result.

The changes, most of which are due to come into force after November 2019, are some of the most far-reaching in Turkey since Mustafa Kemal Ataturk established the modern state in the ashes of the Ottoman Empire in 1923.

The opposition is particularly incensed by a last-minute move by the YSK to accept ballot documents in envelopes without an official stamp.

International observers on Monday echoed some of the opposition concerns, enraging Erdogan.

Up to 2.5 million votes could have been manipulated in the referendum, Alev Korun, an Austrian member of the Council of Europe observer mission, told ORF radio yesterday.

The new system would dispense with the prime minister's post and centralise the entire executive bureaucracy under the president, giving Erdogan the direct power to appoint ministers.

But the 'Yes' vote has even wider implications for Turkey, which joined Nato in 1952 and in the last half century has been engaged in a stalled bid to join the European Union.

Erdogan reaffirmed he would now hold talks on reinstating capital punishment -- a move that would automatically end Turkey's EU bid -- and would call another referendum if the bill did not get enough votes in parliament to become law.

In contrast to the tensions with the EU, Trump called Erdogan to "congratulate him on his recent referendum victory", the White House said in a statement.

Turkish presidential sources quoted the US leader as saying: "I attach importance to our friendship and we have a lot of work to do together."

Meanwhile, the cabinet late Monday agreed to extend the state of emergency -- already in place for nine months -- for another three months.