Mills represents herself in showdown with McCartney over divorce settlement

Sir Paul McCartney and his estranged wife Heather Mills went to the High Court yesterday in the final part of their long-running and acrimonious divorce case.

Ms Mills, who has dismissed her lawyers and is now representing herself, is believed to be claiming up to £60m from the former Beatle.

The case, which is set down for seven days, is being heard under strict rules of privacy before an experienced family law judge.

It was Ms Mills, in a black Mercedes, who first arrived at the Royal Courts of Justice in the Strand, accompanied by her sister, a make-up artist and a member of the public thought to be a McKenzie Friend – an unofficial adviser to help her in the case.

The former model, who lost a leg in a road accident in 1993, was ushered from behind the tinted windows of the vehicle and headed for the nearby court, its windows covered to stop anyone seeing through.

Sir Paul arrived a few minutes later, dressed in a dark pin-striped suit with a black and white knitted scarf draped casually around his neck. Dodging inquiries about the case, Sir Paul simply answered reporters' questions with "Good morning."

Sir Paul is being represented by Nicholas Mostyn QC, one of the country's leading family law barristers, supported by junior counsel and a team of instructing solicitors.

The case raises the prospect of Ms Mills cross-examining her estranged husband about the events leading up to the breakdown of their short-lived marriage.

Yesterday, signs at Court 34 read "No Admittance – Strictly Private".

The couple married in June 2002, four years after Sir Paul's first wife Linda died of breast cancer.

The former Beatle is thought to have amassed a personal fortune of £825m, which is why legal experts believe the final settlement could exceed the current record divorce payout of £48m. Recent big-money cases have shown how the courts are prepared to reward a wife's contribution to a marriage, even if it has not directly benefited the husband's business.

But lawyers agree there are many imponderables that could limit the final settlement, including the shortness of the marriage and the fact the bulk of Sir Paul's fortune was generated long before the couple met.

A key part of the case will be the arrangements for the three-year-old daughter, Beatrice, whose future contact and residence will decided during the hearing. Suzanne Kingston, a family law expert, said: "Current estimates suggest Heather is likely to receive anything from £50m to £100m as her final settlement.

"In Heather and Sir Paul's negotiations, making sure that their child Beatrice is properly provided for will be a key consideration, as will ensuring that there is not a vast disparity between Heather's lifestyle and Paul's as viewed by Beatrice.

"The fact that this has been a short marriage will be taken into account and this could involve looking at the wealth that has been generated during the course of the marriage as distinct from pre-marital wealth."

The only divorces held in public are those where the grounds for the split are contested. The hearing is before Mr Justice Bennett and is expected to run into next week.