The Indiana Senate has approved a constitutional amendment banning gay marriages and civil unions by 40 votes to 10. The public gallery had to be cleared after gay rights protesters shouted at politicians.

Last month, the Republican controlled House of Representatives approved the measure with a vote of 70 to 26.

Today’s session at the Senate was temporarily suspended after around 40 gay rights campaigners shouted “stop hating, stop dividing, stop pandering.”

The proposed law will return to the Indiana General Assembly and must be passed again in 2013 or 2014 in order to be put to voters in a referendum in 2014.

30 US states have constitutional bans on gay marriages, 20 also ban civil unions.