BANGKOK — Thailand’s military junta on Sunday extended its rule by at least seven months when its handpicked reform council rejected a constitution written by its own drafting committee.

The vote was described by some commentators as political theater and contributed to what appears to be growing cynicism in Thailand toward the military’s reign. The vote in the National Reform Council was 135 against the constitution and 105 in favor. The junta will now appoint another body to start the process of writing a new constitution, a process that keeps the military in power well into 2016.

Thitinan Pongsudhirak, one of the country’s most prominent commentators, described the rejection of the constitution as “a sideshow in the junta’s prolonged and indefinite rule.”

Thailand’s military, which seized power from a democratically elected government in May 2014, has given vague promises about a return to democracy. But it seems to be in no hurry to do it.