Sir Ian McKellen fears each script or acting offer he gets may turn out to be his “last job”.

‘The Lord of the Rings’ acting veteran, who turned 85 in May, says his mortality is on his mind so much he now only takes work he knows will be quality in case he shuffles off after it’s done.

He told The Times: “You are aware that this life doesn’t go on for ever.

“If you want to know that you are mortal you just have to look at your address book.

“And so when a script comes through, or the hint of an offer, you think, ‘This might be my last job. No. I’m not doing that.’”

Ian is now playing hard-living raconteur Falstaff on London’s West End in ‘Player Kings’, the director Robert Icke’s three-hour-plus condensation of Shakespeare’s Henry IV, Parts I and II.

He added: “So if Falstaff is my last job, I’d better get it right, hadn’t I?”

Despite admitting he’s now dwelling on death, Ian added he hopes ‘Frank and Percy’ – the play he and his friend Roger Allam, 70, took to the West End last year, will become a film.

And he said he has heard there are “stirrings in Tolkien land” after it was recently announced that ‘LOTR’ director Peter Jackson, 62, will produce and Andy Serkis, 60, will direct a new film in the franchise called ‘The Hunt for Gollum’, which is set to be released in 2026.

When asked if he could reprise his role as the wizard Gandalf in the movie, Ian said that thanks to his part as Falstaff, he’s already got the long white locks for the part.

He added: “I haven’t shaved in months.”

The Times said he admitted he’s heard Gandalf will feature in the upcoming ‘LOTR’ installment, but he added: “There is no script, there is no offer, there is no plan.”

When asked if he would be interested if he was once again offered the part he joked: “If I’m alive.”