A Chicago alderman has, for the second time, threatened to block the opening of a new branch of Chick-fil-A, the fast-food chicken restaurant, which has been involved in a controversy over its apparent opposition to equal marriage.

Alderman Joe Moreno had previously said he had come to the end of a long period of negotiation with Chick-fil-A, and that he would allow the restaurant to open a branch in his neighbourhood, Logan Square, after he announced it had agreed to stop funding anti-equal marriage groups.

The alderman said on Friday “Somebody’s lying to me,” speaking of the promises he announced CEO Dan Cathy had made regarding the company’s opposition to equal marriage.

He threatened that he would block the opening of the restaurant until Mr Cathy “publicly” announced the change of policy to stop supporting anti-gay charities, the Chicago Tribune reported.

In late September, Joe Moreno announced that, after 10 months of negotiations, Chick-fil-A had agreed to stop funding any group with a political agenda, including those opposed to equal marriage.

However, Mr Cathy subsequently confirmed that the company had made no “concessions” over the issue of donations – despite a letter suggesting it had. The alderman had then asked for clarification on the issue, saying:

“It’s pretty simple, Mr. Cathy. Do you acknowledge and support the policies that your executives outlined to me in writing or do you not? Yes or no?” in a written statement.

Mr Cathy kicked up a storm of controversy this summer with comments opposing same-sex marriage.

In July of this year, Mr Cathy said Chick-fil-A was “guilty as charged”, when asked about its perceived opposition to equal marriage.

Long lines formed outside Chick-fil-A restaurants on an “appreciation day” and opponents countered with “kiss-ins” by same-sex couples.

Mr Cathy’s father started the Atlanta-based company in 1967.

The company has issued several statements this year, saying that it does not discriminate on the grounds of sexual orientation.