A deal hammered out between Sir Paul McCartney and Heather Mills in private yesterday may be the most costly divorce settlement in recent years – but it could save the couple as much as £1 million in legal fees.

When divorcing couples fail to agree on a financial settlement, the case goes to trial and the legal costs soar. One leading divorce lawyer said yesterday: “The costs to date in this case have probably reached £750,000 to £1 million already – or more, if you take into account all the public relations teams and others involved. Were it to go to a trial, you are probably talking of doubling that figure.”

But the saving in legal costs is only one key advantage with this kind of settlement, agreed behind closed doors and wrapped in confidentiality agreements. The other is the privacy. To date, each stage of the McCartney divorce battle has been publicly played out in a war of words, public relations spokesmen and media leaks.

But the mass of publicity so far will have only hardened the couple’s resolve to bring the matter to a close in private.

James Stewart, a leading family solicitor with Manches, the London law firm, said: “This case has been very different from other ‘big money’ cases in that it is a real celebrity divorce. So there’s been an element of litigating via PR – and that is highly unusual.”

Yet despite the PR tactics, the pair would have wanted to cut a deal at yesterday’s special hearing, known as a “financial dispute resolution” hearing, he said. “This gives the advantage of a confidentiality agreement incorporated into any consent order which you can’t necessarily get imposed by the court following a final hearing.”

The financial dispute resolution, or FDR, would also enable them to reach more “tailor-made” agreements to suit their respective needs, he said. “When you are sitting round the table you can come up with methods of payment that are tax efficient which is less easy to do at a final hearing. In my experience, no one is really happy after a final hearing.”

The judge in the case, Mr Justice Coleridge, had the task of trying to “bang heads together”. All the offers made are on the table and he indicates the likely award that a court would order, within a range. If the couple refuse to accept his proposal and cannot agree, the case goes to the final hearing before a different judge.

In the case of the McCartneys a trial date has already been set down for next February/March, under Mr Justice Bennett. But that indicates a wish to ensure that the dispute came to the speediest of conclusions, rather than any doubt about the likelihood of a pretrial settlement.Will the media battle have made any difference? One London family lawyer said: “In any big case, people are going to use the media. But whether that would have any impact on the judge I very much doubt.”

Gus Sellito, a director with Byfield Consultancy, said: “The relentless mudslinging and use of the ‘darker arts’ of PR strategy we have witnessed has done little for either of their reputations – unless you buy wholesale into the adage of ‘all publicity is good publicity’ – and is very unlikely to have any impact on the level of financial settlement.”

The couple split in May last year after four years of marriage amid speculation that it could cost Sir Paul as much as £200 million. It took only weeks before the first reports of offers emerged. In August it was suggested that Sir Paul was considering a payout of £35 million.

Then, last October, divorce papers were leaked containing allegations by Miss Mills of violent and drunken and unreasonable behaviour by Sir Paul during their marriage. The press turned against Miss Mills, accusing her of being a gold-digger and fantasist.

She vehemently denied being behind the leak. He was reported as being “shell-shocked” and depressed by the claim; friends said that the allegations were lies.

Throughout, there were snipings in the gossip columns, photo-opportunities – such as Miss Mills having been apparently locked out of one of Sir Paul’s homes – stories about Sir Paul being driven to a psychiatrist and then finally, in May this year, that they had called a truce for the sake of their daughter, Beatrice, 3.

There were the claims and counterclaims over the money. It was reported in May that Miss Mills had offered to settle the divorce weeks before, asking for £100 million and promising silence in return.

Another report suggested that he feared she was out to grab as much as “half” of his £825 million fortune. Reports suggested that she might win nearer £200 million – all perhaps aimed at pushing up a final figure.

It emerged in July that Sir Paul had offered some £20 million – and that she was pushing for £50 million to £70 million. Lawyers say that £25 million to £30 million would be the right figure, but to ensure a line is drawn the sum could be higher.

But what is crucial to any deal is that neither emerges feeling hard done by. “That is the skill of the judge,” one lawyer said. “Both have to feel it is a fair deal.”

Explore Law

• Columnists

• Law Panel

• Law Reports

• Student Law

Times Recommends

• UK legal industry faces loss of 10,000 lawyers
• Curious case of chocolate bunny trademark
• Divorce settlement granted after 22 years