Labour could not have played its cards worse when it comes to Scotland. Years of neglect and complacency were accelerated by the decision to line up with the Tories in the 2014 independence referendum. This was the final straw. The party suddenly and dramatically saw its vote fall off the cliff. Labour's working-class base had a new home to go to - the Scottish National Party. By pitching independence against social justice Labour has made a terrible mistake.

In one sense what the Scottish Labour Party (SLP) does is up to them. But a small and diminishing tail is wagging the UK Labour dog when it comes to talking to the SNP. It can’t go on.

The argument trotted out by Labour in Scotland for decades was that the only way to stop the Tories and get a more progressive society was by voting Labour. Thirteen years of New Labour tested the second half of that offer almost to destruction. Nowhere near enough progress was made and by 2010 the Tories were back – thus fatally undermining the first half of the promise.

Exactly what the difference is in principle between UK nationalism and Scottish nationalism is beyond me. How can support for one patriotism trump another? And independence for Scotland was never about cultural nationalism but democratic nationalism – the right and ability to control your country. When you’ve decided that its impossible to control your country, to make it socially just, while it is tied to whims of the Mail, Murdoch and now May – then the step to independence is a but a small one. Add in Brexit and the prospect of a return to Europe – then what exactly is not to like? For many in Scotland independence and social justice now go hand in hand.

Now on the wrong side of not just the SNP but a myriad of civil society groups who carry the torch of hope in their country, the SLP looks like a rump of angry people who demand that the UK Party must never speak to the SNP. No surrender indeed! Meanwhile they look set to lose every council they run in May - not least Glasgow – with the SNP itching to open the books up on decades of council contracts. At the moment the SLP is fighting it out with the Greens for who is fourth in the polls. Having painted themselves into a corner, they stand holding the brush – furious with everyone who looks on.

For as long as Scotland is part of the union, it is manifestly obvious that Labour in Westminster must talk to the SNP. To believe Labour can revive from its dire polling position, boundary changes, Brexit splits and ever hope to be in government given the loss of its Scottish base stretches the imagination to breaking point.

Now there are two arguments spat back when you suggest this. The first is that the SNP politicians aren’t progressive, so we shouldn’t deal with them. The evidence on that is flimsy to say the least. Of course the SNP can do more - and needs to - on issues of public service delivery. It is handy having the excuse of being tethered to London – "if only we were free". But that can’t be a block on talks that can defeat the Tories – who the SNP have vowed never to work with. Anyway, Labour should be looking to strip away the SNP excuses for any failure – not reinforce them by denying the only route to taking the Tories out. A progressive alliance committed to proportional representation would, at a stroke, end the prospect of Tory majority rule.

The second objection is that fear of the SNP frightens the English horses. We all remember the posters of Ed Miliband in the pocket of Alex Salmond at the last election. Yes it’s a problem – but it’s not going to go away whether we talk to the SNP or not. Last time Labour dealt with it by saying they would never go into government with the SNP. Well, that worked. Voters didn’t believe it and it shed even more votes north of the border.

Labour has no option but to talk to the SNP as part of the now much vaunted progressive alliance. Many in the SNP want to talk to Labour, and the other progressive parties, as SNP MPs Tommy Sheppard and Anne McLaughlin argue in a new pamphlet, The Progressive Alliance: why the SNP needs it.

The SLP should calm down and have a deep think about re-orientating itself – being principally a pro-social justice party that is ambivalent about independence.

If I had a vote in Scotland, I would vote to take a chance and determine my nation's fate, rather than have it settled by the Tory Prime Minister Theresa May in a context set by Rupert Murdoch, the Daily Mail and the demands of the City of London. I would hope for a return to Europe. Looking from the outside, I want Scotland to be as successfully left wing as it can possibly be. Whether in or out the UK, we need a story of success.

If the SLP don't want to wake up and smell the coffee, then fine. But why should they be allowed to take everyone down with them? Labour and the SNP should talk about devolution, proportional representation, fighting bad Brexit and everything that by working together could make peoples lives better. Anything less is indulgence.

Neal Lawson is Chair of Compass, who will be launching a nationwide campaign for the progressive alliance in June.