The military has ruled Myanmar by force for almost all of its post-independence history, before a decade-long democratic experiment gave civilian politicians tentative control.

But the generals took back power in a 2021 coup deposing the government of Aung San Suu Kyi, detaining the democratic figurehead and plunging the country into civil war.

The junta is overseeing a staggered election it pledges will return power to the people after the third and final phase of voting on January 25.

With Suu Kyi detained and her party dissolved, democracy advocates say it has been rigged by a dissent purge and a ballot stacked with military allies in the Union Solidarity and Development Party (USDP).

A USDP official -- speaking anonymously because they were not authorised to disclose results -- told AFP they "won 87 seats out of 100" in Sunday's second phase of the vote.

Combined with confirmed overwhelming wins in the first phase, the official's figures give the party 176 lower house seats so far -- just over half the 330 elected positions, even before the third phase has taken place.

The UN's special rapporteur on human rights in Myanmar Tom Andrews said in a statement last week "the junta engineered the polls to ensure victory for its proxy, entrench military domination in Myanmar, and manufacture a facade of legitimacy".

There are 440 seats in Myanmar's lower house, but 110 are reserved for the armed forces under the military-drafted constitution.

And analysts describe the USDP, many of whose officials are retired officers, as the military's prime political proxy.

Parliament is due to convene in March, when MPs from the combined lower and upper houses will choose the president, and junta chief Min Aung Hlaing has not ruled out resigning as top general to take over the civilian role.