In campaign speeches on state media, candidates cannot criticize the country's powerful army or the constitution it wrote.
Vote spares embattled lower house speaker Shwe Mann, as politicians focus on Nov. 8 polls.
Senior General Min Aung Hlaing says that former junta chief Than Shwe is not involved in political affairs.
Election officials say traveling to polling stations will be impossible because of damage from recent heavy rains.
Former ruling party chief sticks to his guns after sudden ouster last week.
The region appears unlikely to take part in upcoming general elections.
The meeting came as President Thein Sein explained the leadership change at a Union party central executive committee gathering.
Shwe Mann remains parliamentary speaker and will run in upcoming elections, he says.
The move is also likely to affect opposition influence in the legislature, they say.
State of emergency remains in Magwe and Sitgaing Divisions and Chin and Rakhine States
Reports suggest security forces were deployed in the USDP reshuffle.
The owner of the truck discovered hauling the drugs is still at large, police say.
Ruling Union party leaders have not decided on a candidate to put forward in his place.
Myanmar's opposition leader meanwhile urges voters not to split the vote, and to defeat the ruling party in upcoming national elections.
The government reports 56 dead in Rakhine state.
The opposition leader says to vote for the ‘brand,’ not the ‘name tag.’
Negotiating teams fail to agree on which groups can sign the pact.