Of course psychologists weren’t really suggesting that a significant proportion of Tory voters are bashful by nature but were perhaps politely implying there may be a sense of ‘shame’.

Politics in its most basic form is polarised between, on the one hand, those who feel ‘shy’ about their self-absorption and (when the mask slips) their distaste for those they consider are ‘low achievers’, and on the other, ‘progressives’ who seek to appeal to our better instincts (for others, a wider community, the common good, future generations, the climate etc). Less bashful ‘progressives’ may believe they are in a majority when in fact the country may be evenly divided.

Indeed, there’s an assumption amongst many ‘progressives’ that the 2015 general election represented a high water mark for the Tories; that the pendulum will inevitably swing back at the next election, and that scores of Tory marginals will be comfortably won back. A reality check is needed.

My contribution to the book The Alternative which comes out tomorrow (25^th August) reviews the prospects and appetite for cooperation amongst progressives; arguing that those with a broadly centre-left/green/liberal or just plain anti-Conservative perspective should do more to work together, because:

• what divides them from each other is less pronounced than what divides them from Conservatives;
• the Conservatives are quietly rigging and gerrymandering the system to grant themselves a stranglehold on power for decades to come;
• an electoral system which permits – as it does now – Conservatives to secure dominant power when 76% of electors didn’t vote for them needs to be reformed, and it won’t be reformed so long as they have power;
• the majority of non/anti-Tory voters who are not members of the party they vote for don’t understand why politicians who share a broadly progressive perspective seem to spend more time re-rehearsing their disagreements than identifying where they agree;
• if the parties carry on as they are, they will fight each other to a standstill in enough marginal constituencies at the next general election to grant Theresa May a comfortable victory and larger Parliamentary majority.

If progressives are more interested in progressing their policies rather than their disagreements, they will have to find a way of cutting through the tribalism and forge a degree of cooperation.

Since last year’s election I’ve been working with colleagues in the Green, Labour and Plaid Cymru Parties to explore opportunities for effective cooperation. It is evident that, behind the obligation to demonstrate outward self-confidence, realistic assessments of electoral prospects have been made. The Tories’ electoral advantage will be further reinforced by their project to rig and gerrymander the system to their advantage; through:

1. re-drawing constituency boundaries – to the significant benefit of the Conservatives;
2. voter registration rule changes – resulting in the removal of mostly non-Conservative electors;
3. constraints on trade union funding – giving the Conservatives a massive funding advantage;
4. the Electoral Commission effectively sanctioning the Tory ‘carpet bombing’ of swing voters in marginal seats as ‘national’ rather than constituency expenditure – giving the Conservative election arsenal crucial superiority; and
5. the ‘neutering’ of anti-Conservative Scotland from the UK parliamentary arithmetic – giving them the ability to govern even if they lose across the UK.

If the antipathy towards tribalism among the voting public isn’t enough to encourage party tribalists to stop and think, then perhaps the likelihood of growing Tory dominance might persuade them?

The centre-left can do something about it. If we take an 8 per cent swing as a plausible range for an ambitious, effective, campaigning challenger, 102 of the current 331 Tory-held seats are winnable. Of these, Labour are in second place in 76, Liberal Democrats in 22, the SNP one and Ukip 3.. Of course, forthcoming boundary changes will muddy the waters to a certain extent, but it will be possible to extrapolate where the new 100 or so Tory marginals are likely to fall.

In the book I set out a menu of potential initiatives (from non-aggression agreements, jointly selected candidates, Tatton models, VoteSwapping and many others) which cooperative centre-left parties at local or regional levels may seek to act upon.

If progressives don’t cooperate, the chances are they can look forward to decades in the political wilderness as the Conservatives exert a stranglehold on power.

* Andrew George was Liberal Democrat MP for St Ives until May 2015.