The most coveted endorsement in race to be next British prime minister? Margaret Thatcher

Margaret Thatcher has not been in power since 1990. In fact, she's been dead since 2013. But the former Conservative prime minister has been a regular presence in this week's contest to replace Boris Johnson as Britain's next leader.

Thatcher, the most polarising prime minister in modern British history, was reviled and revered in equal measure as she crushed the unions and privatised large swathes of industry.

Tough and outspoken, she led the Conservatives to three election victories, governing from 1979 to 1990, the longest continuous period in office by a British premier in over 150 years.

The frontrunner to be Britain's next leader, the former finance minister Rishi Sunak, has said his economic vision amounts to "common sense Thatcherism" after he clashed with other contenders by refusing immediate tax cuts.

Junior trade minister Penny Mordaunt said this week that, like Thatcher, she has been underestimated because she is a woman. The finance minister Nadhim Zahawi said Thatcher is his political idol and her beginnings as the daughter of a shopkeeper showed him anyone in Britain could succeed.

The candidates are vying for Thatcher's legacy partly because they are trying to charm an exclusive 200,000 members of the Conservative Party who will select the next prime minister, rather the millions of voters as would normally happen in an election. Mostly white, ageing and male, they venerate Thatcher.

"Thatcher remains a political heroine for much of the Conservative Party membership, many of whom are at an age where they vividly recall the Thatcher years and regard them as some of the greatest political years that we have ever encountered," said Jonathan Tonge, politics professor at Liverpool University. "You won't get elected if you criticise Thatcher."

"IRON LADY"

Britain is currently experiencing spiralling inflation, budget deficits, rising taxation, and industrial unrest that, while nowhere near the levels faced in the 1970s and 80s, have sparked headlines that Britain is once again entering a period of stagnation.

In 1979, facing what many British leaders considered an inevitable economic decline, Thatcher launched social and economic reforms, including cutting taxes helped by the discovery of oil in the North Sea. She deregulated the financial sector and privatised state-controlled industries, helping to revive the economy.

While she made millions better off, her decision to close unprofitable industries led to lasting economic scarring across parts of Britain. Unemployment doubled by the mid-1980s to a level not seen since the Great Depression and she remains a hated figure in parts of northern England to this day.

Most of the eight remaining Conservative candidates in the race to replace Johnson are embracing and offering their own interpretations of Thatcher's legacy three decades after she was deposed by her own party.

Sunak said he was following Thatcher's economic approach more than his rivals by being cautious with the country's finances. He likened her upbringing above her father's grocery shop to his own spent helping in his mother's pharmacy.

"You have to earn what you spend," Sunak told the Telegraph. "I would describe it as common-sense Thatcherism. I believe that's what she would have done."

Zahawi, a self-made millionaire who arrived in England as a child unable to speak English, outlined his dream of becoming a modern-day Thatcher. He even went as far to drag her into a policy conversation about obesity.

"When we talk about tax, we talk about freedom," he said. "The freedom to choose what you spend your hard-earned money on, the freedom to choose the food you buy in the supermarket without being penalised by the state for wanting a chocolate bar."

Attorney General Suella Braverman said in May her idols were Thatcher and the wartime hero Winston Churchill.

Another leading candidate, foreign secretary Liz Truss, has spoken enthusiastically for free trade, low taxes, and a small state in an echo of Thatcher. She has previously been photographed in a tank and, on another occasion, wearing a fur hat, evoking famous images of Thatcher during her time in power, when she was dubbed the "Iron Lady".