By Amy Sawitta Lefevre and Panarat Thepgumpanat
BANGKOK (Reuters) - A draft constitution for army-run Thailand to be unveiled this month will be "strong medicine", the constitution panel head said on Wednesday, adding that there was no guarantee it would pass a referendum, meaning a further extension of military rule.
The May 2014 coup ended months of political protests in Bangkok aimed at ousting a civilian government, since when the junta has curbed basic freedoms and pushed back the timetable for elections to 2017.
Meechai Ruchupan, 77, chairman of the Constitution Drafting Committee, said the constitution aimed to solve long-running problems such as abuse of power by lawmakers, but might not solve decades-long political divisions.
"If we are to reform the country, we have to use strong medicine, even if political parties do not agree," Meechai told Reuters in an interview.
"I can't promise it will be Thailand's last constitution."
A previous draft was rejected in September by a now-defunct National Reform Council. Some critics called the draft "unconstitutional" and fear a repeat.
A second failed draft would give the army additional room to prolong its stay in power, say analysts.
"The difference between this time and last time, however, is there might be more restlessness on the parts of political parties, especially if the army fails to show them how they fit into their long-term governance plans," said Ambika Ahuja, Southeast Asia analyst at Eurasia Group.
"The army's main goal is still to prolong its stay in power for as long as possible."
Prime Minister Prayuth Chan-ocha, a former army chief who led the 2014 coup, has publicly said he does not want to hold on to power and that the military is working toward restoring democracy quickly.
Getting a new constitution approved in a referendum is a key part of the junta's "roadmap to democracy" and a 2017 general election. It's also one of the biggest hurdles for the junta, known as the National Council of Peace and Order, because if the draft doesn't pass, it would add to pressure at home and abroad for a quick return to elections.
The interim constitution does not say what will happen if the draft is voted down, leading to more uncertainty.
"I don't know what is going to happen if the charter does not pass," said Meechai.
The constitution would be Thailand's 20th in 84 years of often turbulent democracy.
"Continuous making and remaking of constitutions takes up a lot of political energy, can cause instability and does not allow political arrangements to settle," said Sumit Bisarya, Constitution Building Head of Mission at International IDEA.
For the past decade, Thailand has been locked in a bitter conflict between the Bangkok-based royalist-military establishment and supporters of former Prime Minister Thaksin Shinawatra and his sister, former Prime Minister Yingluck Shinawatra, and their Puea Thai Party.
Meechai said the current draft, running at 261 pages, was not aimed at limiting the influence of the Shinawatra family, which has won every election since 2001, nor that of any political party.
"If people want to vote for Puea Thai, then they will get the vote," he said. "This charter is not designed to be an obstacle to any political party."
The referendum on the draft constitution is expected in July.
(Additional reporting by Aukkarapon Niyomyat; Editing by Nick Macfie)