Myanmar's ruling, military-backed Union Solidarity and Development Party (USDP) has announced that President Thein Sein will not be contesting the Nov 8 general election for a seat in Parliament.

That, however, does not rule out his serving a second term, as under Myanmar's system, the president is chosen by elected MPs.

The army controls 25 per cent of parliamentary seats, to which it appoints MPs, and Mr Thein Sein could be appointed to one of those seats and be voted back into the president's chair.

Vice-President Nyan Tun will also not contest the polls, the party said. The announcement came two days before tomorrow's deadline for the filing of nominations.

The party had not filed a nomination in the President's Naypyitaw ward of Zabuthiri "out of courtesy" in case Mr Thein Sein wished to contest it, USDP general secretary Maung Maung Thein and party secretary Thein Swe told reporters.

They said President Thein Sein had nominated Mr Myat Hein, the Minister for Communications and Information Technology, to contest the seat instead.

The party also said it had not decided on announcing a presidential candidate ahead of the nominations tomorrow.

Well-placed sources in Myanmar have told The Straits Times that the President's family is not enthused by the idea of a second term on grounds of his frail health; he is 70 and has a pacemaker.

Mr Thein Sein himself has not expressed any clear desire for a second term, but significantly has not ruled it out, saying in recent interviews he would be available if asked.

Mr Maung Maung Thein downplayed the expectations of some in the USDP of a big win. "We won over 76 per cent (of seats) in the 2010 election, but in the 2015 election, we won't be able to win like that," media quoted him as saying.

The party faces the National League for Democracy (NLD), which had boycotted the flawed 2010 election. The Nov 8 election therefore is the first serious test for both the USDP and the NLD.

The NLD, driven by the charisma of its leader Aung San Suu Kyi, is expected to emerge as the single largest party in Parliament. But it also has problems - elements of the party are dissatisfied with the way the candidate list was drawn up and Ms Suu Kyi herself cannot be president because a clause in the Constitution bars anyone with foreigners in the family from the post.

Her sons are British citizens.

Given this backdrop, analysts expect post-election bargaining to determine who will become president - and Mr Thein Sein cannot be ruled out.