The House Executive Committee barely cleared a bill to legalise same-sex marriage in the US state of Illinois on Tuesday.

The committee narrowly advanced the legislation with a 6-5 approval to the full House where it is expected to face its toughest test, reports the Chicago Tribune.

The bill has been under increased pressure from anti-gay religious organisations that claim same-sex marriage violates moral and religious principals.

Kellie Fiedorek, an official with the Alliance Defending Freedom, argued that the bill “advances religious intolerance and discrimination towards Illinois citizens with sincerely held religious beliefs.”

However, advocates who are in favour of the bill testified that it was a matter of treating same-sex couples and heterosexual couples equally under Illinois law.

Chicago Democratic Representative Greg Harris said: “What same-sex couples in Illinois want for their families is just what you want for your families.”

The Reverend Otis Moss III, senior pastor at Chicago’s Trinity United Church of Christ, the former church of President Barack Obama added: “We are called to live our faith, not legislate our faith… It’s the charge of civil leaders to ensure that everyone is treated equally.”

The debate was unusually brief for such a polarising issue and the committee members voted late Tuesday evening.

A recent Ipsos poll of Illinois residents has found that half of people living in the state supported a bill to legalise equal marriage, with the percentage in opposition to it much lower.

On Valentine’s Day the Illinois Senate, which is controlled by the Democrats, voted 34-21 to approve the bill to legalise same-sex marriage.