The Illinois chairman of the Republican party has been told that a special meeting will be held today to vote on whether he should keep his position, following his public support for same-sex marriage earlier this year.

State Chairman Pat Brady learned on Friday that Republican party leaders would meet privately this Saturday to discuss his bucking of the party line on marriage equality, and to vote on whether he should be ousted from his role.

In January Mr Brady said that same-sex marriage “honours the best conservative principles. It strengthens and reinforces a key Republican value – that the law should treat all citizens equally.”

Mr Brady said of the special meeting that it enforced public perception that the Republican party is a group of “old white guys”, but said he would respect the decision of the committee.

State Central Committeeman Jim Oberweiss predicted that the special meeting would get the required three-fifths of committee support needed to vote Mr Brady out of the position.

“When you start publicly lobbying against a plank in our state and national party platforms, without even discussing with or advising the board of directors, I think he’s gone too far.

“We’d have exactly the same reaction if suddenly Pat decided to talk about the merits of Obamacare,” Mr Oberweiss added.

The National Organisation for Marriage (NOM) organised a campaign to flood committee members with emails calling for Mr Brady to be ousted. In February NOM pledged to spend $500,000 (£329,000) to defeat any pro-equal marriage Republicans.

Former Republican Governor Jim Edgar, who is anti-marriage equality, said he felt Mr Brady had done “a thankless job”, and cautioned against ousting him from his role, saying the party would be damaged for firing a major figure over their personal view on a social issue.

“If you’re concerned about the future of the party, if this is how it’s perceived, ‘We got rid of him because he’s for same-sex marriage,’ long term that could have a detrimental effect on the party,” he said.

In many ways Mr Brady’s support echoed that of the British Prime Minister David Cameron who said “I don’t support gay marriage in spite of being a Conservative. I support gay marriage because I am a Conservative.”

Just like the Conservative back-benchers in the UK who oppose David Cameron’s support for equality, Republican politicians have condemned Mr Brady’s support.

“I was shocked,” Mr Oberweiss said: “Very surprised. Did not expect that and didn’t know why he would have done that.”

There were even calls from within the party for Mr Brady to resign, which he resisted.

Mr Brady stood by his support saying: “If people want to throw me out because I took on an issue of discrimination [as] the chairman of the Republican Party, the party founded by Abraham Lincoln, then that’s – that’s up to them and they’re free to do it. But I’m not backing down.”