Star Trek’s William Shatner has revealed he never expected to still be celebrating the sci-fi show 50 years after it first aired.

The 85-year-old – who played Captain James Kirk in the classic 1960s television series and the first seven films – quipped that the cast were more concerned about being able to “Klingon” for another series, in a reference to one of the show’s most famous alien species.

William was in Birmingham on Friday for the start of the three-day Destination Star Trek convention at the NEC, with co-star George Takei, who played Hikaru Sulu, to mark the show’s 50th anniversary.

He said the idea of the franchise reaching its 50th birthday had “never occurred” to him during the making of the original series.

The show premiered in 1966 and ran for three seasons on US network NBC before it was cancelled, spawning numerous spin-offs as well as a successful movie series.

William said: “We were always in dire peril of being cancelled, so rather than thinking … 50 years from now, there would be this interest, we were thinking, I hope we can cling on – Klingon, if you would excuse the expression – for another year.”

He put the show’s popularity down to its “mythology” and the freedom within the science fiction genre to imagine anything.

The star also had an awkward interview with Good Morning Britain’s Ben Shepard and Kate Garraway which seemed to suffer technical issues.

After the difficulties, William told the programme: “I’m getting out of this. What kind of interview is this?” He added: “Lovely to chat to you… if that’s what it was.”

Earlier this year, William said he would be “open” to a return to Star Trek, but believes it will never happen.

The most recent movie in the franchise, Star Trek Beyond, was released in cinemas this summer.