Shirley Porter has found sanctuary in Israel, but the bloodhounds of Westminster City Council are closing in

Summers in a luxury penthouse overlooking the Mediterranean. Winters in Palm Springs, California. The odd cruise in the Caribbean or the south Pacific. A light round of golf here, a few games of tennis there. As a pillar of the community, even cocktails are to be enjoyed with the British ambassador and dinners with leading academics.

At 72, Dame Shirley Porter, the Tesco heiress and former Tory leader of Westminster City Council, certainly looks as if she's having the kind of retirement most pensioners can only dream of.

Thirteen years after she was first accused in the so-called homes for votes affair, the woman who masterminded the biggest corruption scandal in British political history is seemingly facing nothing more strenuous than getting her forehand in shape.

Just over a year ago, Dame Shirley was found guilty by the House of Lords of trying to "gerrymander" local elections by selling flats intended for the homeless – to Tory voters. She was ordered to pay £27m, the largest surcharge imposed in Britain, and the first steps were taken towards freezing her assets. In a scarcely noticed move last summer, the surcharge was increased to £36m to include interest and costs.

Yet despite the combined efforts of the High Court, law lords, auditors, solicitors, debt-recovery experts and the occasional private investigator, Dame Shirley has not paid a penny of the fine to this day.

In what could be the most decisive chapter yet in the saga, Westminster council is gearing up for another legal challenge. Within weeks, lawyers for the borough will see a fresh court order, which would require Dame Shirley to reveal for the first time the location of any assets transferred in the past.

It would also freeze any remaining interest she had in them. The Independent understands that a date of 13-15 February has been set for the case in the High Court.

If the order is granted, it could be the beginning of a breakthrough in the affair, offering a way through the maze of overseas funds and transfers that have concealed Dame Shirley's assets. Alternatively, it could mean that investigators find out exactly how impossible recover the cash would be.

The worldwide hunt for the Porter fortune, which was estimated at £69m by The Sunday Times Rich List last year, has not exactly been successful to date. Westminster was granted a freezing and disclosure order by the High Court in December 2001 but during a private hearing a month later, Dame Shirley confirmed the worst fears of Westminster's lawyer. She claimed that her total worth was no more than £300,000.

The Tesco heiress appears to have been most shrewdly advised on her finances at the height of the affair, in 1994. In January that year, John Magill, the district auditor, delivered a damning provisional verdict. Dame Shirley and her colleagues were guilty of "disgraceful" and "improper" conduct and faced huge fines, he said.

Within nine months, she had ensured a drastic change to most of her assets. At one stage she had owned 5.5 million shares in Tesco, the company founded by her father, Jack Cohen, which were worth more than £10m. After 1994, all references to her had disappeared from the company records, either because she had sold the shares or because they had been transferred to another name. According to the company's share register, Dame Shirley made three private share transfers in 1994, with the final move being made on 24 October.

Other investments were moved into trusts in Panama and Guernsey. The Porters used a Guernsey-based share account to shelter their cash from capital-gains tax in the early 1990s.

In 1994, Dame Shirley also sold her luxury flat overlooking Hyde Park to her son, John, and her weekend cottage in Oxfordshire. She and her husband, Sir Leslie Porter, the former chairman of Tesco, left England to live in Israel in the wealthy resort of Herzliya Pituach, half an hour's drive north of Tel Aviv.

Dame Shirley plays tennis at the Arcadia Hotel courts, a couple of hundred yards down the coast from her home. Sir Leslie, who is now 82, keeps a yacht in the Herzliya marina.

Their neighbours are rich Israelis and foreign diplomats. Most Israelis are unaware of their presence, but they are close to the family of the late President Chaim Herzog and have thrown lavish parties for birthdays.

Dame Shirley says that the main reason for moving to Israel was not her financial position, but because she wanted to be near her daughter, Linda, after her grandson Daniel was killed in a car crash in 1993.

Large chunks of the Porter fortune have undoubtedly been sunk into charitable works in Israel. Sir Leslie is the chancellor of Tel Aviv University and has paid for a facility called the UK Building of Life Sciences – The Porter Super Centre for Environmental and Ecological Research. Only a few weeks ago, Dame Shirley opened a conference on Italian and Israeli links on the environment. The Porter Foundation has funded the Porter Institute for Poetics and Semiotics, the Shirley and Leslie Porter School of Cultural Studies, the Cohen-Porter Family Swimming Pool and the Porter Senior Citizen Centre in Old Jaffa.

And yet when their British assets are pursued, the pickings are meagre. Westminster has already obtained a charging order over a flat in central London, in which Dame Shirley's share is understood to be around £18,000. But the flat has a sitting tenant and its value is negligible.

The only things that the council has been able to get its hands on are "certain items of furniture" handed over by the Porter lawyers. Their total value is relatively small. One of the items, bizarrely, is said to be a lavatory seat.

Dame Shirley's son, John, 49, is still based in Britain and is chairman and chief executive of an internet firm called Redbus Interhouse. Unfortunately for Westminster, Redbus makes a loss and Mr Porter says that his own private wealth comes from Californian technology investments rather than from family sources.

Rumours abound of remnants of the Porter fortune in Britain. According to one unfounded account, auditors were on the trail of a £60,000 burial plot in Willesden cemetery, which allegedly had been bought by Dame Shirley. Another unproved claim is that Westminster detected 1,700 acres of Porter-owned Scottish forest in 1996, but the land was sold a month later, possibly after a tip-off was received.

Stephenson Harwood, the City specialist debt-recovery firm hired by Westminster City Council last year, has employed private eyes, or "inquiry agents", to gather information for them.

Most of the £300,000 Dame Shirley admitted to is understood to stem from several paintings – including one of herself, etchings, sculptures and books that are scattered among her family. She has some items of jewellery but claims not to know their value as they are not insured. She also owns a fifth share in a yacht, worth about £4,000.

Precisely because the total value of her assets seems so small, Westminster hopes it can achieve a breakthrough next month with a new court order. "Substantial recovery is dependent on whether assets formerly owned by her can be pursued," a spokeswoman for the council said.

So once again the law courts will decide Dame Shirley Porter's future and the millions that go with it. One thing is not in dispute: Tesco's advertising slogan, "Every Little Helps", has a particularly bitter ring in Westminster.

The liar's tale

May 1986

Local elections see Tory majority on Westminster City Council cut from 26 to four.

Summer 1986

Dame Shirley and others develop strategy to avoid what she calls "the nightmare of Labour in charge of Parliament and Whitehall".

14 March 1987

Secret strategy developed; "Building Stable Communities" aims to shore up Tory vote by selling empty council flats intended for homeless.

1988

Richard Stone, a GP, notices many flats being boarded up and complains. Labour opposition takes up cause.

1989

John Magill, a district auditor, asked to investigate after Panorama exposes scandal.

January 1994

Magill's early findings show Dame Shirley and others engaged in "disgraceful, wilful, unlawful, unauthorised, improper" activity. Surcharge of £21m likely, he warns.

May 1996

Magill's final report finds Westminster "engaged in gerrymandering ... a disgrace-ful and improper purpose". Increases surcharge to £31m.

December 1997

Dame Shirley loses High Court appeal. Branded a "liar" by the judge, Lord Justice Rose. Fine cut to £26m.

April 1999

Dame Shirley wins in Court of Appeal. Lord Justice Schiemann rules it is "legitimate for councillors to desire that their party should win the next election" so "voter-pleasing decisions" are lawful.

December 2001

House of Lords overturns Court of Appeal decision and upholds High Court ruling. Lord Bingham of Cornhill orders £26.4m be repaid.

July 2002

Mr Justice Hart finds Dame Shirley guilty of breach of trust. Raises surcharge to £36.9m.

February 2003

Westminster to apply in High Court for wider seizure and disclosure order to see if it can seize transferred assets.

The balance sheet

The balance sheet

£36,966,542

This is made up of: More than £10m lost in discounts on flats sold, the cost of housing the homeless in expensive bed and breakfasts, the £5m cost of offering incentives to tenants to move out of London, £1m for boarding up empty flats with steel doors, £4m in wasted administration costs, ballooning legal fees and backdated interest.

Personal wealth

£69m

Dame Shirley's total fortune.

Money found/declared

£300,000

Assets mainly made up of paintings, sculptures and furniture but other finances include: £67.25 in a Coutts bank account, originally described as her legal costs fund, £200 in a Guernsey offshore account, an £18,000 share of a flat in London, £20,000 cash balance in a private firm registered in the British Virgin Islands. She owns paintings and sculptures worth about £300,000 and also appears to have a £71 interest in her husband's trust fund.