A gay man in Washington DC claims an airline association paid him “substantially” less because of his sexuality; he is also suing them for being subjected to homophobic abuse by a supervisor.

The Washington Blade reports Stephen Farina, from Arlington, Virginia, first started working as an auditor for Air Transport Association of America – also known as Airlines for America (AFA) in 1992.

However, for the past four years, he has tried talking to management about what he calls discriminatory employment practices, specifically in regards to his pay.

He claims it is substantially lower than his colleagues.

Mr Farina said a promotion to director of industry audits brought his salary up to $68,000 (£42,320)

But when he compared that to others with similar job duties at A4A, he found they were making anywhere between $100,000 (£62,230) and $160,000 (£98,440)

He also alleges that a supervisor made derogatory remarks about his sexual orientation, which he says was known throughout most of his career.

It is claimed the individual repeatedly said that he opposed gay rights like marriage equality and allegedly called Mr Farina a “fag” and a “bonafide bone sucker.”

The supervisor also reportedly made similar remarks to another gay employee.

Mr Farina claims A4A retaliated against him because of his discrimination complaint.

He initially filed a complaint via the LGBT Human Rights Campaign – but decided to drop that in favour of court action.

An association spokeswoman told the Washington Blade: “A4A does not tolerate discrimination in any form and intends to vigorously dispute these allegations.”

A DC judge has already denied A4A’s motion to dismiss the case.

Mr Farina seeks at least $1 million (£620,000) dollars in damages.