He made his comments in a written ruling in which he placed limits on what detail the public could be told about evidence aired at a private family court hearing of the dispute involving Gallagher and Appleton.

The Gallagher case has been analysed in the wake of calls for family courts to be more transparent and at a time when senior judges are in disagreement over how much the public should be told about money fights between separated couples.

Family court hearings are usually staged in private, with members of the public barred.

Rules allow journalists to attend hearings but reporters are not necessarily allowed to publicise detail of cases.

Two years ago, Sir James Munby – president of the Family Division of the High Court and the most senior family court judge in England and Wales – called for ”much more” transparency in the family justice system.

Sir James said the public had a right to know ”what is being done in their name”.

He said an ”informed media” had an important role to play.

One senior family court judge, Mr Justice Holman – who, like Mr Justice Mostyn, sits in the Family Division of the High Court – usually analyses cash fights between separated couples at public hearings.

He says there is a ”pressing need” for more openness.

Mr Justice Holman outlined his views in a ruling on a case in June after sitting in open court to analyse evidence and allowing reporters to name adults involved.

But other family court judges normally sit in private to analyse cash disputes between separated couples.

And earlier this month, Mr Justice Mostyn had said he did not agree with Mr Justice Holman’s practice of hearing divorce money battles in public.

Mr Justice Mostyn had said, in a ruling on a separate case, that such disputes were “quintessentially private business”.

The judge had said it was an issue which should be analysed by the Court of Appeal.

He said today that the state of the law is “chaotic”, and added: “To say that the law about the ability of the press to report ancillary relief proceedings which they are allowed to observe is a mess would be a serious understatement.”

A senior solicitor said the difference of opinion between Mr Justice Mostyn and Mr Justice Holman is making life hard for lawyers and less senior judges.

“Most family law practitioners consider that the starting point of family law cases should be private unless there is a good reason for them to be in public,” said Alex Carruthers, a partner at law firm Hughes Fowler Carruthers.

“In other areas of civil law, cases are conducted in private if they deal with confidential matters or relate to children. By their very nature, most divorce matters have issues which relate to children and have confidential items within them.

“The present situation is unsustainable. Two High Court judges have polar opposite views on the issue. It is impossible to advise a client whether their case could be held in public or in private – it will depend on which judge they appear before. Furthermore, junior judges are put in an impossible position – which High Court judge are they meant to follow?

“If divorce courts become open then there is a danger that a vindictive ex-spouse can use the publicity to try to ‘blackmail’ his or her other half. Plus, even if cases are conducted in private, they can be anonymised and published in legal journals. The public will still therefore be able to assess whether the process is fair.”