Politics has always crept into the scripts of Doctor Who. While researching my book Whovian Dad, it became clear that, with the infinitely-variable formula of visiting any time and place in the universe (and many a disused quarry), it was inevitable that writers would often sneak political allegories into the show.

In the William Hartnell era, with wartime memories still relatively recent, the Daleks had many parallels with the Nazi Party. The militaristic Daleks referred to themselves as “superior beings” and wanted to exterminate all other races. In the 1964 story "The Dalek Invasion of Earth" they saluted with their plunger arms held up as if sieg-heiling, and the Black Dalek was referred to as being their "commandant".

The Daleks’ creator Terry Nation used some very adult themes to reflect 1960s concerns about nuclear war - the Daleks were the result of a massive war with neutron bombs (that destroyed people but not buildings) on their home planet of Skaro. They had designed a metal casing for their mutated bodies and now needed radiation to live.

By the Jon Pertwee years of the early 1970s, Doctor Who had become a bit countercultural, and was reflecting more environmental concerns under producer Barry Letts and script editor Terrance Dicks. In the 1973 story "The Green Death", a company called Global Chemicals had been pouring pollution down Welsh mines, creating giant homicidal maggots (which were actually made from over-stretched condoms by the innovative props department). Global Chemicals was opposed by a group of eco-protestors living in a community nicknamed “the Nuthutch”, and led by professor Cliff Jones, an early George Monbiot-like figure who ends up marrying companion Jo Grant.

In "The Dæmons", Pertwee’s Doctor sounds like a member of Friends of the Earth, telling the Devil-like Azal that through the knowledge he has given man, “he can blow up the world and he probably will, he can poison the water and the very air he breathes". In another Pertwee story ("Invasion of the Dinosaurs") a group of establishment dissidents, including Captain Mike Yates of Unit (United Nations Intelligence Task Force), are so disillusioned by what humanity has done to the Earth that they plan to go back in time to a pre-industrial Earth. The Doctor is starting to sound like a bit of a lefty with lines like: “It’s not the oil and the filth and the poisonous chemicals that are the real cause of pollution, Brigadier. It’s simply greed.”

Industrial disputes and the debate over membership of the Common Market were reflected in the stories "The Curse of the Peladon" and "The Monster of Peladon", featuring striking miners and Peladon debating whether to join the Galactic Federation.

Doctor Who even had a feminist moment when Unit's brigadier Lethbridge-Stewart took a call from a woman prime minister, several years before Mrs Thatcher came to power. Early female companions, like Victoria in the Patrick Troughton years, screamed pathetically when in danger. More positive female companions eventually emerged in the form of the knife-wielding Leela, who starred alongside Tom Baker, and Sylvester McCoy’s companion Ace, who memorably beat up a Dalek with a baseball bat.

By the late 1970s and 1980s some of the struggles on the left had infiltrated Doctor Who. In the Tom Baker story "Destiny of the Daleks", a line of Daleks repeat Davros’ mantra of “do not deviate, do not deviate, let no opposition halt you!” Some suggested that it was a direct reference to the Militant Tendency. The Cybermen were more like the Socialist Workers Party, with their cold, ruthless logic (“you are outside your function!”) and intellectual posturing on the inevitability of the collapse of the Doctor.

Doctor Who had its right-wing moments too, particularly in the Tom Baker story "The Sun Makers" - the tale of a planet stifled by bureaucratic tax collectors.

The Sylvester McCoy story "The Happiness Patrol" in 1988 featured a parody of Margaret Thatcher. Sheila Hancock portrayed a dictator called Helen A, who appeared to have had the same voice training as Mrs T. In another McCoy story, the Daleks were revealed to be Labour-style splitters as Renegade Daleks battled Imperial Daleks in "Remembrance of the Daleks".

Doctor Who was cancelled by croak-voiced Daleks at the BBC in 1989, but when it returned in 2005 so did the political satire. The Christopher Eccleston story "Dalek" had a man in an orange jumpsuit torturing a Dalek in an echo of Guantanamo Bay. Russell T Davies enjoyed himself creating religious fundamentalist Daleks in "Bad Wolf/The Parting of the Ways". "Do not blaspheme!" they ordered, in the style of Islamic fundamentalists like Al-Qaeda. Davies hinted at the contradictions of religious zealotry, too - the implication was that the Daleks had been driven mad by the knowledge that their supposedly pure Dalek DNA now came from filleted human bodies.

David Tennant’s Doctor had his political allegories as well. Alluding to the power of spin, he managed to end the career of prime minister Harriet Jones with four words, by whispering, “doesn't she look tired?” Meanwhile, the Doctor’s old enemy the Master even become PM while posing as Harold Saxon in "The Sound of the Drums". During his year in charge the Master kills a tenth of the population and turns the world into a slave camp, only to be defeated by Martha and the Doctor, and then shot by his wife Lucy Saxon.

In 2007 the Doctor had his first black female companion in Martha Jones, played by Freema Agyeman. When they meet Shakespeare, Martha wonders if his term “blackamoor” is racist, to which David Tennant’s Doctor quips, “it’s political correctness gone mad!”

Sexual politics has been important in new Who too. Russell T Davies created Captain Jack (played by John Barrowman), a multi-sexual space agent who will sleep with anyone in the cosmos regardless of species or gender. Meanwhile, the Peter Capaldi era has already seen the first "lizbian kiss", between Silurian Madame Vastra and her human wife Jenny. In its use of political satire, from non-deviating Daleks to the Master infiltrating British politics, Doctor Who always been astute and often very funny.

Whovian Dad: Doctor Who, Fandom, Fatherhood and Whovian Family Values by Pete May can be downloaded from Amazon Kindle Books.