Andrew J. West stars as Henry in the show, with Dania Ramirez as Cinderella. (ABC/Eike Schroter)

The seventh series of hit ABC show Once Upon a Time is set to include a big LGBT plot, according to the show’s creators.

Speaking at Comic Con this weekend, Showrunner Edward Kitsis confirmed the move.

“I would say that we are planning to do it this year,” he replied, after being asked if the series was planing a “prominent LGBT storyline”.

The show, which is set to return to our screens in October, has explored LGBT relationships before, but this is said to be the biggest plot so far.

Previously Dorothy of The Wizard of Oz and Ruby of Little Red Riding Hood became the series’ first gay couple, 17 episodes into the show.

The relationship received a somewhat lukewarm reception from fans though, who had hoped for a more prominent character pairing.

Viewers had originally speculated that the relationship could occur between Mulan and Aurora – after it was hinted that the pair loved each other – but writers had other plans.

Speaking to Entertainment Weekly about the new plot executive producers Adam Horowitz and Edward Kitsis promised this time a main character would be in line for an LGBT romance.

“One of the show’s franchises is love,” Kitsis explained. “This iteration is reflecting the world today. It will not be anything more than just one of the other love stories that are happening.

“I don’t think it’s an arc,” he continued. “It’ll be a character who is gay and that’s who they are and they exist in the world. They don’t have a sign that says ‘special episode.’”

As yet though, the pair are again keeping tight-lipped on who could be part of the story.

The duo also promised the show would not be “erasing” it’s past, after it cleared out several prominent characters ahead of the series seven reboot.

“We had a plan for the original show that ran six seasons,” Kitsis continued. “At a point we felt like it was time for certain characters to get their happy endings.”

“What we’re going to do now is go on a new adventure.”

The news follows a good year for LGBT diversity in TV, with Doctor Who assistant Bill Potts also openly gay.

Watch the Trailer for Season 7 Below: