In adversity, a strong general and a bit of shooting makes troubles disappear. Like Baroness Thatcher leading from the front, Dame Shirley appears to relish the coming legal battle, which if lost, will mean she shoulders the bulk of a pounds 31m surcharge bill.
Like her mentor, Dame Shirley is the offspring of a grocer. But unlike her Grantham heroine, Shirley Porter's father had a rather wider empire. Her father, Jack Cohen, built up Tesco and in 1989, when her mother died, she and her sisters were each left 19 million shares. Earlier this year, the shares were valued at pounds 56m. Other family assets push her wealth past pounds 60m.
Even before John Magill delivered his final report yesterday, there was never serious worry that surcharging would force the Porters to sell off the family silver. The rise in Tesco shares over the past 48 hours has boosted her wealth by around pounds 900,000.
Mr Magill's report will challenge the determination of the woman that Margaret Thatcher privately regarded as being made of the same stuff as herself. The former prime minister entered politics as a housewife and became the stuff of legend. Friends say Shirley Porter entered politics because she could not stand litter in her streets.
And it was in her streets that the Thatcherite philosophy was practised in full. While timid Tory MPs could only cower in back-bench obscurity, Dame Shirley was the council embodiment of ruthless, market-driven competition. In her dealings at Westminster, Dame Shirley often made the Iron Lady look a paler shade of blue.
The poise she learned at expensive schools in England and Switzerland will help her last the course. She had all the credentials necessary for old fashioned patrician Conservatism. In 1949, she married Leslie Porter, an import and export businessman. He resisted joining Tesco for a decade, but in 1959 joined his in-laws' business and eventually stamped his own brand on the family fortune. He was chairman from 1973 to 1985.
The couple should have looked forward to an easy, carefree retirement. Instead, their homes in Tel Aviv and Florida are now regarded as havens from the Magill fall-out.
In Israel, Dame Shirley is one of the governors of Tel Aviv University and Sir Leslie the Chancellor. In this year's Who's Who, she lists her recreations as golf, tennis, ballet and, ironically, "promoting London".
The seafront home in Israel is regarded by friends as permanent, and the headquarters from where she directs the battle against those challenging the legitimacy of her record in office. Like Lady Thatcher the lady seems not for turning.Reuse content