The attempted assassination of former US president Donald Trump was a dark day for American politics. We don’t know whether the gunman was induced to kill - as some commentators have suggested - by the current political climate. Nevertheless, it appears that the line between passionate criticism and incitement to violence is becoming increasingly blurred. Words matter, but calls to curb speech beyond current laws are immediately met with opposition by those who see freedom of speech as essential to democracy.

And yet, the abuse and intimidation of politicians also threatens democracy. In the UK the government’s adviser on political violence, Lord Walney, has written to the Home Secretary saying there has been a "concerted campaign by extremists to create a hostile atmosphere for MPs within their constituencies to compel them to cave into political demands".

All parties seek to control the narrative through forceful language, hyperbolic rhetoric, and attacks on opponents, but when do words become dangerous? Politics is tribal, but when does tribalism become toxic?

If democracy is a system in which citizens – and tribes – can disagree without resorting to violence, what can be done to strengthen democracy? Is it possible to turn down the political heat without losing the passion?

PANEL: Mona Siddiqui Matthew Taylor Sonia Sodha Inaya Folarin Iman.

WITNESSES: Hannah Phillips - from the Jo Cox Foundation John McTernan - Political Secretary to UK PM Tony Blair, and Director of Communications for Australian PM Julia Gillard Brian Klass - Associate Professor in Global Politics at University College London Nicholas Gruen - policy economist and visiting professor at King's College London's Policy Institute

Producer: Dan Tierney Assistant Producer: Ruth Purser