Maggie’s magic came from her contempt for complacent men

But if the film takes liberties, it is poetically truthful. It is true to the essence of Thatcher, and above all Meryl Streep is amazing. She enters into her; she becomes her: the ruby lips, the flashing eyes, the pineapple hair, the pale skin transpiring at every pore with the fire of pure certainty. Somehow this God-gifted, 62-year-old American actress has re-explained to the world what it was like to see, meet and be the West’s first female prime minister.

Somewhere the film’s director has said that it is a King Lear story, an examination of a tragic loss of power, a meditation on the sorrow of old age. That may have been the intention of the writer and director (neither of whom, I guess, would call themselves ardent Thatcherites) - and yet it is the younger, stronger Thatcher/Streep who seizes the film and takes it over. I watched the matinee in Putney, and most of us agreed afterwards that the dementia stuff was actually quite tastefully done - a sensitive treatment of an important reality for millions of families. We just felt that there was too much of it.

Yes, she is eventually felled by the men in grey suits, but by the end Streep has effectively reminded us of what Thatcher was really all about. It wasn’t just me-first, get-rich-quick, Devil-take-the-hindmost exaltation of the values of Essex Man. That was the caricature. Thatcher herself emerges from this film as a far more revolutionary and inspiring figure - because she was a woman. From the very beginning and at all the critical moments you can see that what really actuated Thatcher was a feminine impatience with the cosy, clubby, complacent politics of the post-war consensus - a consensus that was held overwhelmingly between men of a certain age and class. Of course she believed in thrift and hard work and rewards for merit - but a proper understanding of what Thatcher really stood for is vital today.

To take the issue of the hour, I believe she would have strongly disapproved of boardroom greed. She never really much liked the City - she thought that on the whole the bankers liked interest rates to be too high for the good of her vision of a property-owning democracy. Insider traders were prosecuted on her watch, after years in which such tip-offs had been treated as a “victimless crime” that was traditionally conducted over a vinous, nose-tapping lunch. She got rid of automatic commissions for stockbrokers.

She believed in competition, and allowing the market to work - not stitch-ups. Ask yourself what Margaret Thatcher would have thought of a system where directors sit on each other’s “remcoms” - remuneration committees - and defend each other’s expanding awards, even when the directors in question have presided over commercial disaster of one kind or another. She would have thought it was absurd. Thatcher wasn’t against money, and she wasn’t against pay as an incentive to real exertion and real talent. But - and I have taken the trouble to consult her biographer, Charles Moore, who supports the point - she would have been totally opposed to all that now whiffs of a male-dominated cartel, a you-scratch-my-back-and-I’ll-scratch-yours conspiracy against the shareholders and the wider interests of the company.

Thatcher was brought up a Methodist, with a deep attachment to the values of the Protestant work ethic. She would have been against any kind of crony capitalism, and as for the solution - well, she would not have wanted pay set by politicians, and she would not have gone for any kind of continental-style socialism. But I reckon she would certainly have gone for any kind of poujadiste revolt that gave shareholders a simple way of voting down pay awards they thought were excessive.

In tackling boardroom greed, David Cameron is not bucking the market. He is acting in the true Thatcherite tradition of the Conservative Party, because male clubbiness, jobbery, idleness and complacency were the very things Margaret Thatcher fought against all her political career.