The long, good-natured queues snaking along Brighton seafront to enter Labour’s conference bear witness to the phenomenal rise in Jeremy Corbyn ’s popularity.

And as enthusiasm continues to inflate the red messiah’s standing with the party faithful, grim-faced diehards suffering the blues as they trudge to the Tories in Manchester this time next week will be testimony to the rapid deflation of Theresa May.

When one leader is up the other’s down and the brutal transformation in fortunes over the past 12 months illustrates the explosive volatility of British politics.

Microsoft and Google paying to gatecrash Labour ’s shindig confirms a lobbyist friend’s insistence that all his firm’s clients – big blue-chip corporations desperate for access to power – are clamouring to meet Corbyn and Shadow Chancellor John McDonnell.

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They see Labour as the future and the Tories the past, with May staggering into the dustbin of history as Corbyn talks of hoisting the red flag over Downing Street for up to 10 years.

As Labour brims with confidence and Shadow Ministers talk of when not if they’ll be real Ministers, it’s perhaps time to inject a note of realism.

However, even a scintilla of caution risks being seen as disloyalty when the hall is filled with ecstatic applause.

Of course, Oh, Jeremy Corbyn is entitled to enjoy the Glastonbury cheers when most of his reign was to the backdrop of jeers.

Jeremy Corbyn with John McDonnell (
Image:
DAILY MIRROR)

And the last election was the sweetest of defeats, with Labour stripping May of her majority and future when the Tories had boasted they would wipe out Labour.

Yet it was still a defeat. And if a riven Labour government could survive between 1974-79 and John Major’s squabblers held on between 1992-97, it’s conceivable – even likely? – that in this Bung Parliament another £1billion in 2019 could buy survival for the Tories until 2021 or ’22, with Mrs Mayhem dumped along the way.

So the triumphalism in Brighton could be premature. I hope I’m wrong. You can sniff change in the air. Voters are fed-up with austerity. Labour grasps what needs to be done to build a fairer, better Britain, while the clueless Tories wreak of death.

Brexit remains unstable political nitroglycerin, blowing up a Tory Party which called the referendum for tactical advantage then lost the first of two gambles at the polls.

Jeremy Corbyn in No.10 is an exciting prospect but it would be foolish to rule out third time lucky for undeserving Tories.