James Corden has joked that he's been peeing like a pussy to prepare for his role in 'Cats'.

The 40-year-old comedian will play the wise moggy Bustopher Jones in the upcoming big screen adaptation of Andrew Lloyd Webber's beloved musical, and has quipped that he's been fully immersing himself in the role by living like the animal and using a litter tray to go to the toilet.

Appearing on 'The Ellen DeGeneres Show', he laughed: ''I immerse the character.

''I've just been living as a cat.

''I don't use the bathroom - I have a litter tray ... and that's just what I've been doing the whole time.''

Corden's pussy quip comes after Sir Ian McKellen admitted he wants to find his ''inner pussy'' for his part as Gus the Theatre Cat.

The 79-year-old screen legend recently joked he will embrace his ''moggyiness'' for his performance.

He cheekily quipped: ''I'm looking for the inner pussy - the 'moggyiness' that's within us all...

''I've always wanted to be in a musical on stage so rather late in the day this is like a dream come true.''

Dame Judi Dench - who was due play Grizabella in the original West End production in 1981, until she was forced to withdraw through injury - was the last star confirmed to join the cast as Old Deuteronomy.

Idris Elba is to play villain feline Macavity in the movie, and his alter-ego and his minions capture Deuteronomy in the musical, which is based on 'Old Possum's Book of Practical Cats' by T. S. Eliot.

Taylor Swift (Bombalurina), Jennifer Hudson (Grizabella) and Jason Derulo (Rum Tum Tugger) are also set to appear in the motion picture, which will be produced by Hooper, Tim Bevan, Eric Fellner and Debra Hayward, while Steven Spielberg will be one of the executive producers of the project.