If the bitter Conservative Party division was not enough, Labour has now shown that it, too, has fallen victim to the EU referendum wrecking ball.
Shadow foreign secretary Hilary Benn was fired in the night by leader Jeremy Corbyn. Now ten MPs have quit the shadow cabinet, including shadow Justice Secretary Lord Falconer, shadow health secretary Heidi Alexander and shadow Scottish Secretary Ian Murray.
It is an astonishing revolt and, for any leader, would surely be a mortal blow. For now, Mr Corbyn is supported by shadow chancellor John McDonnell, Len McCluskey, leader of the Unite union – and a large and vocal number of rank and file party members.
Dissatisfaction over his performance has been evident for months. But his lacklustre showing during the EU referendum and the desertion of voters in Labour strongholds to Leave is a huge blow to the party’s standing.
Coupled with the defection of tens of thousands of Scottish Labour voters to the SNP, the party is facing a crisis that threatens its very existence as a credible opposition, let alone a future party of government.
Jeremy Corbyn has been a lifelong sceptic of our EU membership. His evident reluctance to campaign wholeheartedly for Remain testifies to this. Ironically, the quality that helped propel him to the leadership was his authenticity and commitment to principle. This was badly undermined by backing Remain in a most unconvincing manner.
The mass revolt deeply weakens his authority. Now he faces a motion of no confidence. If the party is not to be totally torn apart, Mr Corbyn should resign and allow a new leader to be chosen who can command a team.