Kathleen Wyatt, 55, leaves the Supreme Court after a ruling in her landmark divorce case

In a landmark court ruling, a woman has won a £300,000 share of her ex-husband's fortune - more than two decades after they divorced.

Kathleen Wyatt, 55, had earlier demanded a £1.9 million payout from Dale Vince, 53, although she did not lodge a maintenance claim until more than 25 years after they had separated, and nearly 20 years after their divorce.

The Supreme Court awarded her a £300,000 share of his fortune, which will include legal costs.

Mr Vince is a former New Age traveller who became a millionaire businessman through his company Ecotricity, which he launched years after the couple parted.

Mr Vince, who last year said his ex-wife was 'cashing in on an old lottery ticket', described the ruling as 'mad'.

He said: 'I feel that we all have a right to move on and not be looking over our shoulders.

'This could signal open season for people who had brief relationships a quarter of a century ago. It's mad in my opinion.'

Judges were told the couple met as students, married in 1981 when they were in their early 20s, and lived a New Age traveller lifestyle.

They separated in the mid-1980s and divorced in 1992.

In the mid-1990s Mr Vince began a career in business and went on to become a green energy tycoon after launching a company called Ecotricity - a business group now worth at least £57 million.

Ms Wyatt lodged a claim for 'financial remedy' in 2011.

The success of Ecotricity - which supplies energy to more than 100,000 customers - has made Mr Vince considerable wealth, and he now lives in a £3million 18th century Georgian fort and drives a custom made electric supercar. He remarried in 2006.

Meanwhile Ms Wyatt, has four children by three different men. Her eldest child Emily is a convicted burglar, drug addict and prostitute.

Lord Justice Wilson told the court Ms Wyatt was in poor health and lived in a 'modest house' in Monmouth. He said she sometimes has low-paid jobs, and at other times she 'gets by' on state benefits.

She hired society lawyers Mischon de Reya - who handled Princess Diana's divorce - to fight her claim for a payout.

Mr Vince said he was disappointed with the case and called for a statute of limitations for divorce cases.

Dale Vince (pictured) is a former New Age traveller who became a millionaire businessman years after he and his wife split

Mr Vince, who made his millions running green energy giant Ecotricity, has remarried (new wife Kate pictured)

Deputy High Court Judge Nicholas Francis gave Ms Wyatt's claim the green light in 2012. Three appeal judges blocked the claim in 2013.

But the Supreme Court justices last year said it should go ahead.

One justice, Lord Wilson, said Ms Wyatt's claim was 'legally recognisable' and not an 'abuse of process'.

He said she had been unwise to pitch her claim at £1.9million, adding that an award approaching that size was 'out of the question'.

But he said justices thought that there was a 'real prospect' that she would get a 'comparatively modest award' - perhaps enough to buy a mortgage-free house.

The court heard Ms Wyatt (left) often survives on state benefits, while her ex-husband (right) now runs a multi-million pound company

Lord Wilson described Mr Vince, of Stroud, Gloucestershire, as a 'remarkable man': 'In his 20s he was a New Age traveller with no money at all,' said Lord Wilson.

'But one year at the Glastonbury festival he rigged up a contraption from which he provided a wind-powered telephone service.

'It was the start of a business which, as a result of his ingenuity and drive, has led to his manufacture and sale of green energy on a massive scale.

'His company, Ecotricity Group Ltd, is now worth at least £57million.'

Lord Wilson said Mr Vince lives with his second wife in a Georgian fort.

Approving the terms of the settlement, High Court family judge Mr Justice Cobb, sitting in London, said: 'I am perfectly satisfied that it is reasonable, and that the wife is entitled to receive a modest capital award following the breakdown of this marriage.

'The lump sum payment agreed between the parties fairly represents, in my view, a realistic and balanced appraisal of the unusual circumstances of this case.'

The court heard Mr Vince lives with his second wife in a £3million 18th century Georgian fort (pictured)

Lord Justice Wilson told the court Ms Wyatt was in poor health and lived in a 'modest house' in Monmouth (pictured). He said she sometimes has low-paid jobs, and at other times she 'gets by' on state benefits

Neither Ms Wyatt, of Monmouth, nor Mr Vince, of Stroud, Gloucestershire, were in court for the announcement of the settlement.

However, speaking after the ruling, Mr Vince said: 'I am pleased to confirm that the financial proceedings brought by my ex-wife – now 32 years since our separation – have been concluded.

'This case has been a terrible waste of time and money on a meritless claim.

'I'm disappointed that the Supreme Court decided not to throw out the case, given it was brought over 30 years since the relationship ended. We'd both moved on and started families of our own.

'The passing of time was extremely prejudicial, it's been so long that there are no records, no court has kept anything, and it's hard to defend yourself in such circumstances - indeed the delay itself has enabled the claim, because there is no paperwork in existence.

'There clearly needs to be a statute of limitations for divorce cases - a time limit beyond which a claim cannot be made. Such a thing exists in commercial law for good practical reasons. It's six years, which is plenty long enough to bring a claim. Divorce law needs to catch up.