British politics is fractured and chaotic – but at last it’s brimming with ideas for the future | Polly Toynbee

Finally, Labour is talking policy, thanks to the leadership contest and Tony Blair’s intervention – and the centre-right is making a much-needed fightback too

“Wouldn’t it be great if Tony Blair kept his mouth shut about the Labour party?” Readers may have cheered that Guardian letter-writer’s response to yet another infuriating assault by Blair from the outer-stratosphere of nowhere. Isn’t Labour in enough trouble with a life-or-death byelection against the forces of darkness without incoming fire from its former leader?

Actually, no. His intentions may not have been benign, but Blair does Labour and national politics a favour, prising open the political omertà preventing serious discussion within parties. There can’t be a new prime minister installed without an honest reckoning of the precarious state of the nation.

Polly Toynbee is a Guardian columnist