BANGKOK (REUTERS) - Thailand will hold a general election in 2017 even if a draft Constitution does not pass a referendum this year, Prime Minister Prayut Chan-o-cha said on Tuesday (Jan 26).

Political instability has haunted South-east Asia's second biggest economy for the past decade and promises on a return to democracy from the military government, which came to power after a 2014 coup, are closely watched.

The government had previously made a new Constitution a prerequisite for a general election, but Prayut said a vote would go ahead in mid-2017, even if it had to be held under an old Constitution.

"No matter whether the draft constitution passes the referendum or not, the government will hold the election in 2017 according to our roadmap," Mr Prayut, a former army chief who staged the 2014 coup, told reporters.

The junta, known as the National Council for Peace and Order, has curbed dissent and pushed back the timetable for elections to 2017, raising concern about the prospects of a country that was for years hailed as a shining example of a fast-developing Asian economy.

At the heart of the fractious politics is rivalry between the Bangkok-based royalist-military establishment and populist former Prime Minister Thaksin Shinawatra and his allies, who the establishment sees as a threat.

A decade of tumultuous politics has included two coups, five elections and bouts of civil disobedience and street violence in which scores of people have been killed.

A junta-appointed committee has written a draft for the country's 20th charter and is expected to unveil it on Friday.

A military appointed "reform council" rejected a previous draft in September. This time, the government will put the draft to a referendum, which is expected in July though no date has been fixed.

Democracy activists and some political parties say the charter will undermine the development of democracy and result in weak coalitions easily manipulated by the military.

Mr Meechai Ruchuphan, chairman of the Constitution Drafting Committee, told Reuters in a interview last week the Constitution was aimed at resolving long-running problems such as abuse of power by lawmakers.

Contentious articles include provisions that empower a Constitutional Court to intervene in political conflict, a partially or wholly appointed Senate and provisions for an unelected prime minister.

Mr Prayut did not say why he wanted an election even if the draft is rejected, but his announcement is likely to ease concern that a return to democracy could be repeatedly derailed.

"I promise that in July 2017 there will definitely be an election," he said.