Sienna Miller has ended her relationship with Jude Law four weeks after it was revealed that he had an affair with his children's nanny.

The 23-year- old actress has told friends she has struggled to forgive the movie star - but feels she can no longer trust him.

As she finished with Law, she was seen crying outside the home they once shared. She is said to be ' completely distraught' at the break-up.

'They have tried to make a go of it, but it comes down to the fact that Sienna can't trust Jude,' said a source close to Law. 'She really thought their relationship was something special and was completely in love with Jude. But Sienna can't forgive Jude's betrayal - particularly as at the same time he slept with the nanny he was trying to convince her to have a child with him. Jude has done everything he possibly can to try to win her back.

'He even spent several hours with her mother in a bid to get her to try to change Sienna's mind.

'They have been spending a lot of time together over the last few days to try to get their relationship back on track, but all they do is row. And now they have decided that they are better off apart.'

The couple spent most of yesterday arguing and were even spotted having cross words in 32-year-old Law's car after a meeting at the house they used to share in Primrose Hill, North London.

Miss Miller was later seen sobbing outside the house before leaving to do a matinee performance of As You Like It at Wyndham's Theatre in the

West End. Last night, Law took her out to dinner at the fashionable J Sheekey restaurant near Leicester Square, but was unable to change her mind.

'Jude has pretty much given up,' said the source. 'If Sienna can't forgive him after all he has done to say sorry, then there really isn't anything more he can do.

'He feels he has made a public apology and shown her just how much he loves her. He sees what he did as a silly mistake and as something that Sienna should get over.

'He is now planning to go on holiday and has even spoken to his ex-wife Sadie Frost about joining her and their kids in Ibiza.

'As far he is concerned, it is over - although with these two anything could happen.'

Only a day earlier, it had appeared the couple were planning to mend their relationship when they were pictured out together for the first time in weeks - walking their dog on Hampstead Heath.

Nanny Daisy Wright revealed last month how she had an affair lasting several weeks with Law while she was away with him and one of his children in New Orleans.

The star admitted his betrayal in a public apology, saying: 'I'm deeply ashamed and upset that I have hurt Sienna and the people most close to us.'

Ironically, the break-up comes just a few weeks after the couple were finally able to marry - because Law only recently settled his divorce with Miss Frost, the mother of his three children.

Last night, a spokesman for the couple said he could not comment on their relationship.