Sir Paul McCartney’s ex-wife Heather Mills is back in court, but this time it’s for a new ‘cause’ – the model’s nanny has sued her over allegations of sex discrimination and intimidation.

Sara Trumble has claimed that she was made to work as late as midnight, blow-dry Heather’s hair and even give the former model naked spray tans.

The 24-year-old minder says she was only supposed to look after Beatrice, now aged five, Heather’s daughter with ex-husband McCartney.

But she now claims that her job was changed when she went back to work after taking maternity leave earlier this year, reports the Mirror .

A constructive dismissal claim was lodged with an employment tribunal last week.

The two sides have 28 days to come to a negotiated settlement or face airing their dispute in open court.

Sara resigned in September and, after an argument with Heather, refused to work her notice.

Heather’s rep said: “This claim will be vigorously defended.”

It is expected Heather will argue that Sara was a housekeeper as well as a nanny, and that she bought her a car, took her on holidays and allowed her to work flexi-time after she became a mum.

Sara will claim that, since leaving her job, she has felt intimidated by Heather who has demanded she keep silent about everything she saw and heard while working for her.

Sara claims she had to be at work at 7.30am some days to blow-dry Heather’s hair. And once a week she gave Heather a naked spray-on tan.

The last time Heather appeared in a court she dumped a jug of cold water over the head of her husband’s divorce lawyer Fiona Shackleton and was branded a fantasist by the judge.