US comedy Glee has been criticised for using the word ‘tranny’.

The show, which has been commended for its approach to LGBT issues, had a Rocky Horror-themed episode last week, in which the cast took on roles from the 1970s musical.

In the storyline, actor Harry Shum Jr.’s character Mike is given the role of Frank-N-Furter, who dresses in stockings, high heels and lingerie.

But he has to abandon the role because his parents don’t want him to look like a “tranny”.

The Gay and Lesbian Alliance Against Defamation (GLAAD) said that the word was a “slur” and condemned the show for not having another character criticise the use of the word.

GLAAD said: “The casual manner in which the word was used is jarring, even if he [Mike] may have been repeating what his parents said.

“This inclusion of this slur is particularly alarming given last season’s powerful episode in which Kurt’s father chastised Finn for using the word ‘f*g’. That episode sent a powerful message to the show’s young fanbase that words have power and they can hurt.

“Unfortunately the larger problem here is that the word ‘tranny’ has become an easy punchline in popular culture, and many still don’t realise that using the term is hurtful, dehumanising and associated with violence, hatred and derision against transgender people – a community that is nearly invisible in media today.”

The Rocky Horror episode was also criticised for cleaning up some of the musical’s most famous lines.

In Sweet Transvestite, the word “transsexual” was replaced with “sensational”, while another song saw “heavy petty” being replaced with “heavy sweating”.