A gender non-binary couple have taken part in a fiery debate on Good Morning Britain (GMB) as they defended their identities.

Just days after a top London private school announced it was considering introducing its first gender neutral uniform, Northamptonshire Police unveiled a gender-neutral cap, and on the International Day Against Homophobia, Transphobia and Biphobia, Fox and Owl appeared on GMB to explain what it means to be gender non-binary.

Fox Fisher was assigned the gender of female at birth and later began undergoing a gender transition but "realised I was going from one set of expectations to another set of expectations, because there are extreme expectations for men and women in this world."

While Fox said their gender expression was more masculine "I define as non-binary", meaning neither fully male nor fully female.

The opposite is true for Owl Jónsdóttir who was assigned male at birth.

Owl explained why neither of them identify as either male or female: "There are very strong ideas about what it is to be a man and a woman in our society, and those ideas are entirely socially constructed.

"The things we expect men and women to do, and as a trans-person who has been perceived as a man for most of my life, who transitioned, I noticed how people perceived you differently and these expectations."

Although host Piers Morgan said he supported "all transgender rights" and praised the pair for going "through what you go through, and I totally respect it and want total equality for you," the debate became heated when Morgan asked if he could identify as a black woman.

When both Owl and Fox replied that gender and race were two different issues, Morgan branded their response as "hypocrisy" and "an inconsistency".

Fox replied that Morgan could "identify in any way" he wanted, while Owl pointedly remarked: "This is a hypothetical, intellectual discussion for you, but this is about our actual identities."

Fox continued: "This is our lives, not just a four-minute segment for you."

The programme again became heated when Morgan referred to children "running riot" in schools wanting to identify themselves as gender non-binary and went on to say the idea was spreading among children "like a contagion".

Fox responded that the decision to identify as gender non-binary was not a "contagious" one, while Owl pointed out that it was "not a disease".

The pair again became exasperated in the interview when Morgan questioned if he could identify as an elephant, be "afforded elephant rights" and let into London Zoo.

Fox responded that such an argument was "silly" when "48% of trans youths are attempting suicide".

Throughout the interview the pair were keen to stress that they did not want to "erase gender, we're not saying people cannot be men or women, we're saying people can also be non-binary".

Owl stressed: "You need to respect people's gender and their identity and their right to identify."

Morgan then went on to label children who identify as non-binary as part of a "fad", a comment the pair strongly denied.

Morgan then asked if the pair "abide by the rules of the land", continuing: "Is gender not a societal thing that we should just respect and acknowledge and that's the way it is?"

Owl explained: "It's not about being cool, it's about an inner-sense of self and identity."

While Fox questioned that "isn't everything subject to change?"

As Susanna Reid attempted to bring the interview to a close, Fox fired a parting shot at Morgan while also attempting to promote his new book (Are you a boy or a girl): "It's for children aged three and up so it should be good for you Piers."

Following the interview - which began trending on Twitter - Stonewall the LGBT equality charity tweeted Morgan, accusing him of "attacks on non-binary people".

Morgan replied via Twitter that it was his right to have an opinion.