A new centre ground party could finally provide a functioning opposition to Theresa May's hard Brexit

Brexit has cut across party boundaries; our party system can no longer accommodate the new dividing lines. It is no longer about socialism versus capitalism, or working class versus ruling class

Anna Soubry, a Europhile Conservative MP, has spoken of her openness to a new centre party

The chattering classes are chattering about creating a new centre party again. Pro-Europeans in Labour, the Conservatives and Liberal Democrats make common cause over their concern that the UK might be heading for an economically damaging hard Brexit.

Richard Dawkins, the scientist, has proposed a "European Party" pitched at the 48 per cent who voted Remain last year. He said it might not win the next general election, but would “stand a better chance than Labour or the Lib Dems under their present name”. He was writing in the New Statesman, which has a dramatic cover saying: “Wanted: an opposition.” Anna Soubry, the Europhile Conservative MP, teased the magazine that she might be open to joining a “moderate, sensible, forward-thinking” new party. When pressed later, however, she insisted that she is a One Nation Tory.

Such public hints reflect many private discussions among politicians who wonder whether they have more in common with like-minded liberals in other parties than their own. They sniff something in the air after Brexit left the 48 per cent largely unrepresented. Brexit has cut across party boundaries; our party system can no longer accommodate the new dividing lines. It is no longer about socialism versus capitalism, or working class versus ruling class. As well as close links to the EU, centrists in all three parties support a market economy with strong public services; they are broadly pro-immigration and socially liberal.

Yet politicians break party bonds only when there is a big enough catalyst. Walking out on your political family is hard. For the Labour moderates who formed the SDP in 1981, Labour’s hostility to Europe amid its lurch to the left pushed them over the edge. Sound familiar? Today Labour’s pro-EU wing are furious with Jeremy Corbyn for giving Theresa May such an easy ride on Brexit so far.

Potential Labour defectors do not rule out forging a new party, but insist the stars are not aligned yet. Corbyn’s internal critics are convinced the tide is turning against him among once-loyal party members who now accept he is not up to the job. His MP opponents have stopped attacking him in public, claiming the Corbynistas have nothing to say when they cannot blame Labour’s dire opinion poll ratings on “bitter Blairites.”

Critics ask why they should surrender Labour’s brand and assets to the left. They suspect the trade unions will force Corbyn to fall on his sword before the election, so it would be odd for them to walk out now. The SDP is not a good advert. It did not break the political mould – even though it forced Labour to return to the centre – and by splitting the non-Tory vote, helped keep Margaret Thatcher in power.

With just nine MPs, the Lib Dems ought, in theory, to be keen on a realignment. But Brexit has revived the party and given it a huge target audience, so it would be a strange time to gamble on a new venture. Although Cameronites exiled by May enjoy a little mischievous plotting with Blairites and their former Lib Dem coalition buddies, May has a nuclear weapon to force Tory MPs into line: “Do you really want to throw Labour a lifeline and scupper 20 years of Conservative rule?” Tory whips deploy it against the party’s 30 pro-EU MPs.

So perhaps a more realistic prospect in the short term is a progressive anti-Tory alliance by Labour, the Lib Dems and Greens. It would have to be grassroots driven rather than imposed from the top; indeed, there are growing signs of anti-Tory pacts at local level. Less painful than political divorce.

Another barrier to a new party is the absence of a leader with the star quality and fresh appeal of Emmanuel Macron, who is prospering in France under a presidential rather than party-based system. It would be easy for opponents to portray Tony Blair, George Osborne and Nick Clegg as a coalition of yesterday’s men and losers (and some Labour figures say “the Austerity Chancellor” might be a hard sell to Labour members and voters).

Yet the chatter goes on and politicians who might be tempted to take the plunge see two scenarios in which it might just happen. One is Corbyn leading Labour to a catastrophic election defeat, with its number of MPs falling from about 230 to 150. The left keeps its grip on the party through rule changes and deselecting centrist MPs, who form the New Democrats with the Lib Dems after their recovery fails to translate into big parliamentary gains. With the UK still in a transitional exit deal from the EU, a group of Tory Europhiles sign up and the new party offers voters a choice between Return and Leave in another referendum.

The second scenario is more immediate: despite May’s genuine desire for an EU deal and her professed support for “liberal democratic values,” her party drives her to a hard right Brexit under a World Trade Organisation regime. The pound plunges and the economy sinks. This is a sufficient catalyst for Labour, Tory and Lib Dem figures who want a soft (or no) Brexit to throw off their party chains and start over in the hope that shaking the kaleidoscope prevents a bad Brexit. On balance, I doubt it will happen. But stranger things have.