Firstly, I should perhaps counter the two negative reviews by pointing out the novel this was based on was written in the early 1980's when a left wing Labour government could have been a distinct possibility. Thatcher was VERY unpopular as Chris Mullin was writing his novel. But, had Tony Benn replaced the ineffectual Michael Foot as Labour leader - again very possible then -he would have been no Harry Perkins. Lacking the fictional characters street smarts and possibly, wider appeal. But this is fiction after all.
By 1988, when this superb drama was made, Thatcher was still there but the adaptation, with now great foresight as current events show, made more of Perkins rise being due to uncovering massive scandal and criminality in big finance.
Mullin himself was a left winger, though he moderated his views with maturity and, as he himself admitted, the changes in the political landscape. As a well respected MP for Labour from 1987 to 2010, he would vote for Tony Blair as leader in 1994 but against the Iraq war in 2003.
Mullin represented a seat in Sunderland in NE England which suffered terribly under the Tories. He was a very effective Parliamentary Select Committee Chairman then had a series of junior ministerial appointments, the often 'Yes Minister' or even 'The Thick Of It' like events he had then are recounted with his trademark humour and self deprecation in his dairies,
The Novel and this adaptation crop up in these widely acclaimed dairies of his life, political and personal, that have been published over the last few years, he kept them from 1994 to 2010.
If there was a 'Mullin' character in the book and TV show, it's 'Fred Thompson' played by Keith Allen, like Mullin when he wrote the book, a campaigning journalist, though as described in the book as rather more physically like the author than in the TV film, not to take anything away from Allen's performance.
I cannot add much more to the mostly positive reviews, that this was shown in 30 countries, won a stack of awards, was cited by Mullin's political allies and opponents years later, is testament to the novel and this excellent, so well made and acted drama.
I will add that though I'm left of centre, I would not have supported Harry Perkins anti nuclear, anti NATO policies. Not that this in anyway reduced my enjoyment of this drama which I've watched and enjoyed many times.