A Scotland Yard police officer in London is now the first gender-fluid officer in the United Kingdom, switching between a male and female identity, depending on which particular one the officer feels like that day.

Metropolitan Police have issued the officer two separate warrant ID cards: one for his male name, Callum, and one for her female name, Abi, after launching a diversity project encouraging the officers on their force to "be themselves" at work, according to The Sun.

Calling the initiative "Bring Your Whole Self to Work," the department sent out an internal memo to all 43,607 officers announcing the news.

Callum, who was born a male, is a 13-year veteran on the force and said he was happy to hear of the recent changes accepting his lifestyle.

"The first time I walked into a Met building as Abi, I was hyperventilating so much I almost passed out," the officer said. “I’ve done it a handful of times since and felt so happy that I got to be me at work."

He stressed that he was still the same person, regardless of who he was identifying with on that particular day.

"Abi is a part of me that exists and I want that part to be recognized and validated. But I’m still me," he said. "I’m still the same person whether I’m presenting as Callum or Abi. It’s the same dice. You’re just looking at a different number."

Retired Detective Chief Inspector Mick Neville criticized the move, saying it was a waste of funding that could be allocated to more deserving projects.

"Senior officers constantly complain about lack of funding. But there will always be enough to fill a diversity unit to run crazy schemes like this," Neville said. "Little wonder the public lose faith in the police."