A bill to legalise equal marriage in the US state of Minnesota, will go to the State House floor on Thursday, possibly suggesting that its advocates have gathered enough votes for it to pass.

House Speaker Paul Thissen had said he would not schedule a vote on the bill until he knew it had the necessary 68 votes to pass.

On Monday evening, backers of the bill said they had the votes, but did not go further to specify the number they did have in support, reports Pioneer Press.

Leaders in the Senate also said they had enough votes to pass the bill, and scheduled a last-minute hearing for Tuesday on the fiscal impacts of legalising equal marriage. The Senate Finance Committee will review the bill.

Those in support and opposition to equal marriage have been putting increasing pressure on lawmakers to publicly reveal which way they intend to vote on the measure.

Minnesota State Senate members on the Judiciary Committee, as well as the Civil Law Committee in the House, in March passed the equal marriage bill.

After hearing almost three hours of testimony, the Senate committee passed the bill 5 votes to 3, along party lines, and the House committee voted voted 10 to 7 for the bill.

In November 2012, Minnesotan voters avoided a constitutional ban on marriage equality, and pro-equality campaigners have since stepped up efforts to push for equal marriage to be legalised.

A group opposed to equal marriage in the state has pledged half a million dollars to defeat any Republican legislator voting to legalise marriage equality.

On 6 November, voters in Minnesota voted ‘no’ on Amendment 1, a constitutional amendment that would have defined marriage as being a union solely between a man and a woman.

Washington, Maine and Maryland legalised equal marriage in referendums in those states on the same day.