By Andrew R.C. Marshall
BANGKOK (Reuters) - The ouster of a powerful political rival less than three months before a landmark election in Myanmar was dramatic confirmation of President Thein Sein's desire for a second term in office, analysts said.
Shwe Mann was removed as chairman of the ruling Union Solidarity and Development Party (USDP) on Thursday after security forces surrounded its headquarters in the capital, Naypyitaw.
Both Shwe Mann, long considered a presidential frontrunner, and the USDP's secretary general were replaced by Thein Sein allies.
The move carried echoes of the ruthless purges carried out by the military junta that ruled Myanmar until 2011. Both Thein Sein, whose five-year term ends next March, and Shwe Mann are former generals.
"This is a reminder of a very unhappy past," said Khin Zaw Win, director of the Tampadipa Institute, a Yangon-based think tank which advises some Myanmar lawmakers.
"This opens the way for (Thein Sein's) second term," he added. "His main rival is now gone."
Thein Sein's only other rival had been opposition leader and Nobel peace laureate Aung San Suu Kyi, but she is banned from the presidency under a military-drafted constitution that the president has shown scant interest in changing.
"If this is a way to strengthen his hand, then he's a potentially much stronger candidate than anyone else in the field right now," said Christian Lewis, Southeast Asia political risk analyst at Eurasia Group.
On Nov. 8 Myanmar will hold what could be its first free and fair elections in 25 years.
According to a USDP statement on Thursday, Thein Sein "transferred the post of party chairman" to his ally Htay Oo. Shwe Mann retains his influential position as speaker of Myanmar's lower house.
But the speed and manner of the USDP shake-up could force a reassessment of a bookish-looking president who has sent mixed messages about his ambitions.
On July 13, a presidential staffer told Reuters that Thein Sein, who is 70 and wears a pacemaker, would not seek re-election due to health reasons. The next day, another staffer denied this.
"The president has not publicly ruled out running in the election or trying for the presidency for a second term," said Zaw Htay, a senior official at Thein Sein's office.
Zaw Htay also told the Irrawaddy, a Myanmar news service, that the president was "quite healthy".
Thein Sein was appointed Myanmar's prime minister in 2007. Shwe Mann was number three in the same junta, which that year brutally snuffed out democracy protests led by Buddhist monks.
A U.S. embassy cable called Thein Sein a "consummate insider," while pro-democracy group Altsean Burma described him as a desk-bound officer who "lacks ambition."
By contrast, Shwe Mann, who is two years his junior, was a battlefield commander who won the military title "thura" for bravery.
Both men were close to retired dictator Than Shwe, and both stood as candidates for the USDP, a party the military created.
Shwe Mann replaced Thein Sein as USDP chairman in 2011 after the president had embarked on a series of political and economic reforms.
But he antagonized the still-powerful military by forging relations with Suu Kyi and backing her campaign to change the constitution, which grants Myanmar's generals sweeping political powers.
Even if Thein Sein chooses not to contest the parliamentary elections, he could still be nominated as the next president by members of parliament under Myanmar's military-drafted constitution.
"He doesn't need to (run)," said analyst Khin Zaw Win. "He can stand as a candidate and he has the backing of the military."
(Additional reporting by Aung Hla Tun and Timothy Mclaughlin in YANGON and Amy Sawitta Lefevre in BANGKOK; Editing by John Chalmers and Mike Collett-White)