The 34-year-old `Pushing Daisies` actress and `Harry Potter` star DavidThewlis, 47, have reportedly called time on their nine-year relationship after their work commitments forced them to spend more and more time apart.
A source close to the couple - who have a five-year-old daughter Gracie together - said: "Things have not been great for a long time and they have tried to keep this quiet to protect everyone.
"It certainly did not help that Anna and David have been forced to live apart for so long, but there are other issues at hand that have made them realise the relationship was over."
Although they have separated, the former couple will spent part of the festive season together and have pledged to stay on good terms for the sake of their daughter.
The insider added to the Daily Mail newspaper: "They do care about each other very much, and the most important thing now is that they both continue to be the best parents they can be for Gracie.
"They will have to see each other over Christmas at some point, but hopefully it will not be too painful."
Last December, Anna was pictured kissing 23-year-old actor Joseph Cross, who she was starring with in a stage production of `Breakfast At Tiffany`s` in London`s West End, but pals insisted the pair were just friends.
A source said at the time: "Anna is queen of touchy feely - but they`re just good friends."