Japan’s casino plans appear guaranteed after the legislature’s upper house voted to amend the constitution on Wednesday.

The Diet’s upper house approved the Integrated Resorts Promotion (IR) bill in a plenary session that extended into Wednesday night. The bill, which underwent amendments during the upper house debate, must now by law return to the lower house for rubber-stamping.

Wednesday marked the final day of the Diet’s extraordinary session, but the ruling Liberal Democratic Party (LDP) voted to extend the session by three days to ensure the IR bill wouldn’t fall victim to procedural restrictions. The amended IR bill is expected to be approved by the lower house on Thursday morning.

The upper house vote came despite a joint no-confidence motion filed by four opposition parties – the Democratic Party, Japanese Communist Party, the Liberal Party and the Social Democratic Party – that was ultimately vetoed by the LDP. The motion injected further delays into the process, leading the LDP to push for the session extension, which was supported by the lower house.