18/04/2017 09:06 BST | Updated 18/04/2017 09:06 BST

There's Only One Way To Prevent A Tory Landslide

Johnny Greig via Getty Images

Even as today's announcement is sinking in, the metaphorical wind is being sucked out of not very billowy political sails. 'Oh shit', is the general and not unreasonable reaction from many progressives.

May's move to call an election for June 8 is audacious and bold. If successful she will at a stroke win a larger majority and a clear, hard Brexit mandate as well as annihilating Labour; perhaps wiping out the UK's main left wing party for a decade or more or forever. This is history in the making; an unraveling that began last June and whose complex, interwoven political fabric we have yet to appreciate fully.

Nothing in any polls suggests May is wrong, but it is a gamble she is taking.

Not all of the electoral maths favour the Conservatives. In 2010, against a Labour Party tainted with blame for the finance crisis and that had in any case run out of steam, Cameron failed to win an overall majority. And even in 2015, with Labour wiped out in Scotland and the Lib Dems similarly expunged from many English seats, the majority in terms of seats was a narrow 12. Psephologists' long-predicted slide towards coalition government in the UK is still underway.

It remains the case that many suburban, coastal, midlands and south west seats are swing-able - think Yeovil, Eastbourne, Kingston, Battersea, Corby, Loughborough. However, they are only likely to be swing-able if there is a progressive alliance.

With Labour on its knees and the Lib Dems' resurgence underwhelming and not very surgey, the only way to prevent a paradigm-shifting Conservative majority with and a government with a mandate for a nasty and dangerous hard Brexit is for Labour, Lib Dems and Greens to collaborate and back only one candidate in swing seats; the one with the greatest chance of winning.

Couple this with the fact that remainerism remains strong in many constituencies and with Scotland's desire to fast track to devolution and you have a potent mix of issues that could, with guile and resource, be bridled in the progressive interests.

There's a whole range of reasons why this won't happen. The Lib Dems will regain some seats anyway, so Farron will be able to hang on as leader and paint 2017 as a partial recovery. Labour is led by a decent but incompetent, inveterate back bench contrarian and will not be able to overcome its innate tribalism and sense of electoral entitlement. The Greens believe - wrongly - that they can grow as a Parliamentary force.

Plus electoral collaboration to stop a Conservative landslide would be a big gamble; it's not known how voters would respond and it's probable that a 'vote Farron, get Corbyn' defence from the Tories would be very effective. But how else can the almost inevitable be prevented?

The 'oh shit' outcome appears most likely. May's right-wingers, her appeasement of hatred and de facto tolerance of racism; her transforming of the UK into a tax haven and her championship of the hardest of Brexits that will deprive our children of their future as Europeans is the fate that most likely awaits us.

Unless of course the progressive parties can work together. History, and not their own electoral gain, is in their hands.