As the Illinois state legislature ponders whether to pass a marriage equality bill next week, Modern Family star Jesse Tyler Ferguson is in the state trying to drum up public support for Illinois to become the 10th state in the US to allow gay marriage.

On the ABC sitcom, Ferguson portrays Mitchell Pritchett who is raising a young daughter with his spouse Cameron Tucker who is played by Eric Stonestreet.

'I can't imagine who's a fan of [Modern Family] would want to deny Mitchell and Cameron the chance to get married, if for nothing else, for amazing TV,' told the crowd during an event in Springfield. 'A vote for marriage equality today does not diminish the unions of millions of citizens enjoying traditional marriage. It does nothing to threaten this infrastructure, and yet a vote for marriage equality does everything for us.'

Off-screen, Ferguson is engaged to Justin Mikita with whom he has founded Tie the Knot, a non-profit organization that sells limited edition bow ties and donates the proceeds to charitable organizations that support same sex marriage.

The Religious Freedom and Marriage Fairness Act is sponsored by Senator Heather Steans. There is very little time to get the bill passed before the new legislature is slated to be sworn in on 9 January.