All three parties have their most left-wing Leaders ever. The Conservative and Labour ones have attracted popular attention in a way that has not been seen simultaneously since the heyday of Ted Heath and Harold Wilson. Moreover, the Liberal Democrats are increasing in membership, in funds, and in vote share.
As the largest political party in Europe, Labour does not even notice the loss of a number of members comparable to the electorate of one parliamentary constituency, but spread across the entire country. That handful of people comprises the sum total of those who were ever New Labour, as such, to the extent that they would leave Labour if it ever stopped being like that, but would not therefore go back to the Conservative Party, since they had never come out of it in the first place.
Of course, they could hardly attach themselves to the Conservative Party now, with its talk of workers' and consumers' representation in corporate governance, of shareholders' control over executive pay, of restrictions on pay differentials within companies, of an investment-based Industrial Strategy and infrastructure programme, of greatly increased housebuilding, of action against tax avoidance, of a ban on public contracts for tax-avoiding companies, of a cap on energy prices, of banning or greatly restricting foreign takeovers, and of banning unpaid internships.
Yet that is as far right as British politics, rather than political commentary, now goes. There is no potential electorate to the right of that. Merely because a few newspaper columnists hold views that could be so classified, then that does not mean that anyone else does. UKIP managed to fail to win even Stoke Central, even this year. It has never won any seat without the incumbent MP as its candidate. But it managed to lose half of those in 2015. That left it with one MP, and he pretty openly wants to quit.
By very stark contrast, within the present decade, Scotland, Wales, the South of England (outside London, please note), and the North of England have all elected MPs from outside the Labour Party who were to the left of most Labour MPs and of the then Labour Leadership. Scotland, Wales and the South still have such MPs, at this very moment.
It would be quite a job to be to the left of the present Leader of the Labour Party. But the most active, and by far the best known, candidate at the impending Manchester Gorton by-election is undeniably to the left of most Labour MPs. He is on course to be elected to Parliament as many times as Nigel Farage has failed to be so.