Richard E. Grant ''had'' to make 'Can You Ever Forgive Me?'.

The 61-year-old actor was instantly won over by the script for the drama - a true story about struggling biographer Lee Israel who began forging letters by dead celebrities - because of the way it captures the fragile bond between people, and thinks the friendship he struck up with co-star Melissa McCarthy was reflected in their performances on screen.

He said: ''Friendships are so important to me but they are also fragile and the film captures that brilliantly.

''The script was so smartly written and compassionate, I had to do it.

''It's based on the true story of Lee Israel and the friendship between her and my character, Jack Hock - two people who are essentially failing at life.

''They go through the cycle of friendship, the falling-in-love stage, the loyalty, then the inevitable betrayal and reconciliation, which is all the more poignant as Jack is dying of AIDS in the 1990s and we also got on really well, so that affected our performances and made our on-screen friendship doubly charged.''

The 'Withnail and I' star is ''so grateful'' for his career and can't imagine retiring any time soon.

He told Psychologies magazine: ''I'm so grateful for my career and I'm enjoying it for as long as it lasts.

''Other actors my age, such as Daniel Day-Lewis have retired and I could never imagine retiring now.

''I've heard that, as a method actor, he finds the process incredibly draining but I don't take my characters home with me, I don't have to live the life of that person, so it doesn't drain me the same way.''