The couple - who got engaged last July after dating for one year - reportedly broke up last month although the 'Inception' actor is said to be desperate to rekindle their relationship.
A source told the Metro newspaper: "Tom and Charlotte broke up last month. He has been calling her a lot to try to patch things up."
Tom, 33, and 28-year-old Charlotte first met on the set of the TV adaptation of 'Wuthering Heights' when they were cast as star-crossed lovers before going on to work together again in television drama 'The Take'.
Speculation about the couple's relationship has been mounting after Tom failed to make an appearance at Sunday's (13.02.11) BAFTAs where he won the Orange Wednesdays Rising Star Award.
He is said to have sent an apology blaming "personal commitments" for his absence.
He has a two-year-old son Louis Thomas Hardy with ex-girlfriend Rachael Speed.
Tom - who battled alcoholism and a crack cocaine addiction in his early-to mid-twenties - revealed last year he had relationships with men when he was younger.
He said: "I'm an actor for f**k's sake. I've played with everything and everyone. I love the form and the physicality, but now that I'm in my thirties, it doesn't do it for me. I'm done experimenting."