Broadcaster Jonathan Maitland says his play depicts the conflicted loyalties of Mrs Thatcher’s back-stabbing chancellor Geoffrey Howe

What is it with writers and Mrs Thatcher? Here’s a by no means complete list of recent films and plays about her with the relevant actress listed alongside.

1) The Iron Lady: Meryl Streep.

2) Margaret: Lindsay Duncan.

3) Handbagged: Fenella Woolgar and Stella Gonet (This play featured two versions).

4) The Long Road to Finchley Andrea Riseborough.

To which we must now add : 5) Dead Sheep: Steve Nallon.

Budding Sherlocks will notice that the role of the ex Tory PM is being played by a man this time. I’ll explain the thinking behind that shortly. First, the key question: why write a play exploring what one theatre critic has called “well ploughed territory”?

For a start I would argue that this play isn’t actually about Margaret: the protagonist is Geoffrey Howe, her former Chancellor and Foreign Secretary, the “Dead Sheep” of the title.

(“Being attacked by Geoffrey Howe” said his political rival Dennis Healey, “is like being savaged by a dead sheep.”)

It portrays the agonising conflicts of loyalty that led to Howe’s famous 1990 resignation speech, which triggered Mrs Thatcher’s downfall. He had been loyal to Margaret for years : but he was also loyal to his wife Elspeth, who disliked Margaret intensely. He was also loyal to the concept of Europe, which Margaret very openly undermined, often in crude, playing-to-the-gallery fashion. Nevertheless, even as a supporting player, Margaret’s extraordinary personality backlights everything in our play vividly, almost overpoweringly.

Writers are drawn to her for many reasons. Chiefly of course because of the Iron-like strength of character. (I would have called her the Granite Lady :Granite is naturally occurring and more interesting than iron, but there we go.)

We want to explore how she managed to succeed so phenomenally as a woman in such a Jurassic, all-male world.

Documentaries and news programmes can only partially explain it: drama fills in the gaps.

She was almost comedically Manichean, a gift to any film or play. She saw the world in black and white. You were for her or against her. Hence her routine description of Socialists as ‘”The Enemy”. She was also an extraordinary mixture of femininity and ruthlessness. Thus President Mitterrand’s observation that she had “the mouth of Marilyn Monroe and the eyes of Caligula.”

The character is compelling then, but so are the circumstances. The Thatcher decade was arguably one that changed our country more than any other. We entered it in black and white but exited in colour. In 1980 unions held the whip hand, key industries were nationalised and millions lived in low rent, state-owned housing. In 1990, when she left, all that had changed and Greed Was Good. To write about Margaret is to write about Britain at its most compellingly tumultuous.

Margaret was also famously described as “the best man in the cabinet” which brings me to what one theatre producer friend described as “your brave and risky casting decision.”

For us, recruiting Steve Nallon was something of a no brainer. If you’re trying to differentiate yourself from all the other Thatchers then casting a man is a good start. And there was indeed something male about Margaret:the way she bullied the slightly long-winded Geoffrey in front of her cabinet for example. She would, it is said, constantly exhort him to “for goodness sake get on with it, Geoffrey !”

Another reason for choosing Nallon is that he isn’t just any old actor : he has a Phd in Thatcherology . He knows which dress she wore to the 1989 Madrid Summit, the fine details of her economic policies and, crucially, the difference in timbre between her 1980 voice and the 1990 version. Which is he why he portrayed her so brilliantly on the satirical TV show Spitting Image for so many years. Steve’s performance in “Dead Sheep” is, to my mind, something more than acting: it’s a mesmeric, almost creepy, inhabitation of Mrs Thatcher.

This dramatic field may indeed be a tad “well ploughed” then. But I suspect the literary tractors will be returning to it for some years to come...

Dead Sheep by Jonathan Maitland runs at The Park Theatre from April 1 until May 9.