Parliament begins debate on Thursday on a proposal to allow same-sex marriage. The matter has been considered before, when 76 MPs signed a previous bill. That attempt fell at the committee stage thanks to opposition from Finns Party, Christian Democrat, Centre and National Coalition MPS.

That setback sent campaigners back to the drawing board, and they returned with a campaign to force the issue via Finland’s law on citizens’ initiatives.

The law ensures that any proposal that secures 50,000 signatures must be considered by MPs. The Tahdon 2013 campaign launched its petition, and over six months it was signed by 166,000 people.

The proposal was presented to speaker of parliament Eero Heinäluoma in December. After the initial debate on Thursday it will pass once again to the Legal Affairs Committee.

Tahdon 2013’s polling on the issue shows support for gay marriage running at 58 percent, with 34 percent of those polled opposed to the idea. Some 42,000 people have signed a petition opposing legal changes.