Angelina Jolie welled up at the London press conference for her new film, Changeling, today.

The 33-year-old tried to hold back her tears when she started talking about her mother, Marcheline Bertrand, who died in January 2007 following a seven year battle with cancer.

Changeling, which is released in the UK next week, tells the true story of Christine Collins whose child was abducted in 1928.

Jolie said she related to her mother when taking on this role; drawing comparisons between her strength and that of Christine Collins. 'My mother was very much Christine,' she said.

'We called her Marshmallow as a joke because she was just the softest, most gentle woman in the world. She would never get angry. She couldn't swear to save her life but for her kids she was really fierce. So this was very much her story in that she was the woman I related to. She had that strength for her children.'

The mother of six also revealed that it was not always her intention to star in the film. 'When I first read the script I said no. I found the subject very difficult. But then I couldn't stop talking bout this extraordinary woman. I really wanted to do this as an extra piece of justice for her.'

Even when filming there were difficult times. 'As a mother it was horrible,' she said. 'I would just run home to my kids at the end of the day and just be very goofy and silly with them. I was so happy that those kids were ok.'

Her family commitments will also see her cut down on work. ' I am not making some retirement announcement but I don't know when I will work again. I have lots of responsibility at home.

'I have the good fortune to financially not have to work all the time. So maybe once a year, maybe eventually every two tears and then maybe I'll stop.'

Asked whether she will have any more children, she replied, 'I'm sure I will.'

The Changeling is hotly tipped for Oscar nominations. If Jolie wins an Academy Award here's hoping she doesn't misplace it. She cannot find her Oscar for Girl Interrupted in 2000.

'I gave my first Oscar to my mom. She was one of those people that didn't put things around that she thought were too special and no body knows where she has hidden it,' she laughed.

But Jolie would be pleased with another award. 'It is always nice if someone acknowledges something you have worked hard on that means a great deal to you,' she said.