The dramatic ouster of Mr Thura Shwe Mann and 11 other leaders of the ruling Union Solidarity and Development Party (USDP) in an internal purge on Wednesday night left Mr Shwe Mann still as parliamentary Speaker but likely eliminated his prospects for the presidency in the Nov 8 election.

The move stacked the USDP with allies of President Thein Sein, turning a second term for the 70-year-old from a possibility into a probability.

The purge shows that Myanmar's fragile experiment with democracy still depends on personalities as well as walking a thin line that does not upset the military elites.

It is a line, analysts say, that President Thein Sein is more acutely aware of than the ambitious Speaker. It also makes the political landscape ahead of the election clearer.

Mr Shwe Mann was known to have developed a close alliance with opposition leader Aung San Suu Kyi - a factor that contributed to his downfall as the army establishment has long been wary of the National League for Democracy (NLD) leader.

As a result of the purge, therefore, there is a closer convergence of interests between the USDP and the military, and a separation of interests with the NLD.

The NLD has also in effect decided to contest the election on its own without erstwhile allies in the influential 88 Generation group, which comprises pro-democracy activists who were students during the 1988 crackdown by the former junta.

While Mr Shwe Mann was vigorously pursuing reforms, the tension with the President's office was less ideological and had more to do with dissonance between personalities, and between the institutions of Parliament and the executive.

"Styling the purge a victory of conservatives over progressives is extremely misleading," Myanmar historian Thant Myint U told The Straits Times. "You'll find reformists and hardliners and the full mix of motives in both camps."