Like the glowing end of a Morland cigarette, the Corbyn spy smear has burned brightly and will now be tossed into the gutter to add its smoke to the B-movie atmospherics of this Tory government.

“It’s not that Corbyn is a spy, or that he was paid by Russia” – is the line now coming out of conservative journalism – but that “he can’t be trusted” and “always sides with Britain’s enemies”.

That was always the intention the Sun, Telegraph and Mail had when repeating – without any proof – the lies of a fantasist. And of Conservative politicians like the defence secretary, Gavin Williamson, when he accused Corbyn of being disloyal.

In the past 24 hours the Sun’s political editor, Alex Massie of the Spectator and liberal Tory mouthpiece Matthew d’Ancona (in the Guardian!) have all made the same point: Labour can’t be allowed to take power in Britain because it habitually “supports our enemies”.

What’s happened, in short, is the classic right-wing smear operation against Labour that has been wheeled out again and again since the fake Zinoviev letter scandal which cost Labour the 1924 election.

D’Ancona, rightly, points out that the past is important: indeed the right-wing elite which runs Britain is engaged in a pretty continuous struggle to recount its own version of history – from Dunkirk to the Abdication crisis back to the mass slaughter of the 1914-18 war and the Russian revolution.

The left should be proud of its own past. In the 1980s Corbyn – like me and many current Labour members over the age of 45 – was on the side of the miners when they were declared the “enemy within”. He was on the side of Liverpool at a time when the Tory economic adviser Keith Joseph advocated letting the city rot. And at a time when the USA was preparing for a “winnable nuclear war” Corbyn stood for unilateral nuclear disarmament.

It’s no surprise to those of us who did this to be called “enemies of Britain” now, because that’s what we were called then.

When we stood outside British prisons saying the Birmingham Six and Guildford Four were innocent – when the courts still said they were terrorists – we always assumed that the barking police dogs and long lenses trained on us were backed up by a spying operation. We now know Special Branch sent people not only into movements to support the human rights of UK citizens wrongly locked up for terrorism, but into the animal rights movement, CND, the Stephen Lawrence campaign and the wider left.

We were called enemies and treated like enemies. The British state was at war with the labour movement, with inner city black and Asian communities, and with half the population of Northern Ireland.

So ask yourself why, two years after inviting former IRA prisoners to the House of Commons, Jeremy Corbyn would try to stage a secret meeting with his Czech intelligence “handler” – this is the word d’Ancona uses in the Guardian – in the tea room of parliament.

It’s clearly ludicrous. The Czech government’s own archivists say it’s unfounded. And it’s a rerun of the same smears anti-communist factions have been running against social democrats and left-wingers across eastern Europe for decades.

But the questions ‘why this’ and ‘why now’ are interesting.

Why now is easy. The Conservatives are in deep trouble. They are realising they have no chance of achieving the ‘hard’ Brexit they promised their xenophobic supporters. Whether in or out of the customs union, in or out of the single market, Europe is determined to insist on ‘equivalence’ for any trade deal, meaning it’s impossible to begin doing bilateral deals with countries outside Europe.

In all serious studies of the Brexit impact, only the ability to slash wages, slash safety standards, food hygiene regulations and environmental controls makes up for the hit to growth that happens because we leave the single market. This is what Empire fantasists like Jacob Rees-Mogg told themselves Britain could achieve.

Yet it’s not going to happen. Instead May will attempt to bring a half-hard Brexit to parliament, as late as possible to meet the deadline of the vote Labour forced them to hold, and she will lose it

If she survives that long – she may not – Theresa May’s government will fall. And they’ll then have to fight an election. Only this time “trust me I am competent” will not work. The old “Corbyn’s an Islamist terror sympathiser” will not work either – not with police organisations screaming about cuts to frontline policing.

So May has decided to fight the coming snap election to “defeat socialism”. This was her promise made in a speech at the Black and White Ball, quickly followed up by the Daily Telegraph’s page heading “Socialist Threat” over the Corbyn smear, and by an email to Tory members asking them for money, again, to help “defeat socialism”.

But the Brexit fiasco is only half the story. May’s Conservatives do not have a majority in parliament – so they are reliant on the DUP, a sectarian unionist party in Northern Ireland. The DUP, having taken a £1bn bribe to support the Tories, is now effectively demanding a return to direct rule in Northern Ireland, effectively scrapping the Good Friday Agreement that brought peace, and an element of shared sovereignty, with the Republic.

Now the same Tories calling Corbyn a traitor and a spy are the ones calling for London to scrap the historic pact with Dublin, to which the European Union is a signatory.

In summary, to save their skins they are prepared to re-ignite the conflicts that scarred British society in the 1980s: the cold war, the Irish war, and the dirty intelligence war on ‘domestic subversion’.

The left should refuse to engage.

The radical social democratic project in Britain is – rightly – premised on the assumption that these conflicts are over.

In the 1980s, it is true, the left opposed the wars, the invasions, the suspension of human rights, the targeted assassinations and the arms build-up of Britain and the USA – not because it supported the USSR or the IRA, but because it saw the detrimental impact on our own human rights, our own security and indeed – in the case of nuclear war – the survival of life on the planet.

Today Labour is, and has to be, prepared to run the British state. That means overseeing the peace process in Northern Ireland, managing armed forces with anti-terror commitments and bases across the globe, and placing under democratic control the police forces and surveillance bodies that once kept files on Corbyn, John McDonnell and Diane Abbott. It means honouring Britain’s Nato commitment to spend 2% of GDP on defence and renewing Trident.

But it will also mean major change. The likelihood of a Labour government selling arms to Saudi Arabia while it bombs the children of Yemen into starvation is zero. The same goes for arms to the semi-dictatorship that runs Turkey. A Labour government would be an enthusiastic co-participant with Dublin in restoring devolved government to Northern Ireland, and would discard the Tory fantasy of an Empire 2.0 involving the white, English speaking nations of the Commonwealth.

It would, I hope, reserve the right to alter Britain’s nuclear posture; and restructure the armed forces to defend Britain against two major threats – Russia in east Europe and terrorism (both jihadist and far-right) at home. It would have little appetite for the Tory policy of ‘global reach’.

But to be against global reach is not to become an enemy of your own country. To support the participation of Sinn Féin in the governance of the six counties is not the equivalent of treason. To democratise policing, so that the horrendous practices being exposed among the undercover cops who haunted the left in the 1980s can never happen again, will enhance the national security of this country, not harm it.

If Corbyn were really suspected of spying, the security service should open a file on him, report its contents to the privy council and kick him off this semi-secret body appointed by the Queen. In fact, Corbyn, McDonnell and Abbott are all members of the privy council and have sworn or affirmed its oath of secrecy.

From their attacks on the Good Friday Agreement to their spy smears against Corbyn, the Tory right are burning the bridges of bipartisanship within the parliamentary system.

If they lose the next election, in addition to splitting, it is highly likely that the Tory right will attempt to portray a Labour government or Labour-led coalition as unconstitutional, and encourage extrajudicial action to undermine it. Its opening weeks would be met with constant destabilisation tactics by the press – the same kind of unsubstantiated stories as now but on steroids.

The ‘run on the pound’ which May constantly warns about would become Tory strategy. The same general who threatened a military coup when Corbyn won the leadership will, no doubt, be wheeled out by his Sunday Times minders to threaten one again.

What is at stake then, that a section of the Tory right is prepared to use language close to incitement against Corbyn? What’s at stake is the entire corrupt system which pays for the yachts, ski lodges and offshore accountancy industry that the elite relies on.

For the tax dodgers, their law firms and accountants, the Empire 2.0 fantasists and the privatisation leeches, a Corbyn government really will feel like the world ending.

What they really fear is that, with a social democratic government committed to liberal, universal principles of human rights and justice, the British people get to see – for the first time in many decades – a Britain committed to peace, coexistence and international justice – and that the majority of British people will prefer it to the Tory project of post-imperial bluster, xenophobia and random expeditionary wars.

That’s why they still treat the labour movement as the enemy within.