The former MI5 boss Stella Rimington claimed at a literary festival last week that some of the people advising Jeremy Corbyn were “familiar names”, allied to “various subversive organisations that were identified as wishing to destroy the democratic system of this country”.

I don’t advise Corbyn, but I am pretty sure my name is on Dame Stella’s secret list. I was on the far left in the 80s. I actively supported the steel strike, the miners’ strike and the print strike. I opposed the Falklands war and the first Iraq war. I stood outside provincial jails shouting slogans suggesting – rightly, it turned out – that the Birmingham Six and the Guildford Four were innocent. In 1993, after Stephen Lawrence was murdered, I went on a protest march through south-east London where white racists shouted threats at us from their gardens. The police feigned deafness.

Throughout this time, it was the job of special branch, not just to “find out who they were”, as Rimington suggests, but – as we now know – to disrupt the left’s activities, form fraudulent sexual relationships with activists and, in the case of the Lawrence murder, smear the victim’s family. What MI5 did is subject to the Official Secrets Act, but, given that it bugged and burgled ministers from the Wilson administration in the 60s, one can assume it was very similar.

Rimington told visitors at the Cheltenham literature festival that the presence of people once targeted for surveillance around Corbyn is “quite an ironic turn of events”. In fact, it is a wonderful advertisement for democracy.

The idea that the left, the miners and various environmental groups wanted to “destroy the democratic system” in the 80s was pure paranoia. If it had been true, then the thousands of hours of intelligence work at the time would have led to arrests and trials. Whatever it said in the turgid, theory-laden journals the left published, what we wanted was a left Labour government. We believed it would have to be supported by extra-parliamentary action if sabotaged by the deep state. The politicisation of policing during the miners’ strike reinforced that view.

But that world is gone. Corbyn, who himself was targeted by MI5 and special branch, could soon be prime minister. With the Human Rights Act, the creation of a supreme court and the operational policing changes in the aftermath of the Macpherson report, the legal framework around policing and intelligence has tightened. The real “ironic turn of events” is that the police, armed forces and intelligence services stand to be better funded and staffed under a Labour government than the present one.

The questions remain: who ordered Rimington to put the left under surveillance in the 80s, and on what grounds? There was a clear national security rationale when it came to the Communist party: it was logical to ask whether Soviet intelligence was trying to manipulate it. But Rimington wasn’t targeting the KGB: she ran an agent inside the National Union of Mineworkers, sent in “to destabilise and sabotage the union at its most critical juncture”, according to Labour MPs who signed a Commons motion.

Amid the social warfare of the 80s, there are people from both sides who could say, as Rutger Hauer does in Blade Runner: “I’ve done questionable things.” Unless we’re going to have a South African-style truth and reconciliation process, the challenge is to bury the paranoia and move on.

It matters because a new kind of radical social democracy stands on the brink of government. It wants to save British capitalism from wage stagnation, grotesque inequalities of wealth and the kamikaze mission of a no-deal Brexit. It wants to rescue democracy from the layers of indifference that led to the Grenfell Tower disaster. It has boosted democratic engagement, especially among the young, by building the biggest mass political party in Europe.

There is zero chance of an extrajudicial reaction to a leftwing Labour government – the scenario depicted in Chris Mullin’s novel A Very British Coup. From top to bottom, the UK’s armed forces, security services and police are acutely aware of constraints on their activities by the rule of law.

The law enforcement culture that allowed undercover cops to perpetrate abuses is, we must assume, gone. Likewise, by implication, the culture that allowed MI5 to “destabilise and sabotage” an entirely legal trade union must be assumed to have gone. When a serving army general told the Sunday Times in September 2015 that “the army wouldn’t stand for” a Corbyn government, few people took it seriously.

Today our country is under threat: from Isis and other terrorist organisations; from Vladimir Putin’s Russia, which is waging hybrid warfare on all western democracies; and other state actors, such as with the alleged Iranian cyber-attack on parliament. The security services are our first line of defence and they need our support, as do the police and special forces who stand ready to deal with situations such as the London Bridge attack. It’s a sign of the maturity of our democracy that – in the middle of a bitterly fought election – the political parties were able to maintain cross-party unity in the face of the terrorist attacks. Briefings by unnamed former members of the security services, again designed to smear Corbyn, were largely shrugged off by the electorate.

The demand for democratic change in Britain is strong. Attempts to revive the paranoid practices of the Thatcher era would have no consent among the electorate – and in an information society would be much more easily exposed. My advice to Stella Rimington is to stop replaying the 80s, get on with the 21st century and cease trying to manipulate legacy intelligence for political ends.