PRESIDENT Trump, Brexit and a resurgent far-right could be the start of a crisis which imperils “the basic features of a civilised and democratic society”, Patrick Harvie has warned.

The Scottish Green co-convener also criticised centre-left politicians for failing to respond adequately to the economic crash of 2008, and so helping lay the ground for today’s populism.

In a speech to the David Hume Institute in Edinburgh, the Glasgow MSP said that if the progressive forces who bungled the global economy wanted to re-set the agenda, they would need to “abandon” the centrist thinking of recent decades.

“As we see the crumbling of support for once-powerful social democratic parties in Europe and the US, it should be clear that they no longer offer the world what is needed, if they ever did.”

In a speech called How to prevent a good crisis going to waste, he said: “Progressive forces around the world should be ashamed of ourselves for collectively failing to offer a successful response to the economic crisis which began a decade ago, or to the ecological crisis which has been building for far longer, and today’s dangerous resurgence in far right movements owes a lot to that failure.”

He said the nominally centre left let “de-regulated, free market ideology of neoliberalism become so entrenched” in its own thinking, that it was unable to offer any alternatives.

“They were reduced to promising ways of getting back to business as usual, ignoring the fact that business as usual had been letting people down for far too long, driving both social inequality and environmental destruction,” he said.

“What we now see, in Brexit, Trump, and other far right movements could be the beginnings of yet another crisis, in which the basic features of a civilised and democratic society are in peril.

“Or, it could be taken as an opportunity for progressive forces around the world to re-set the agenda and establish a positive and empowering vision for the future, which rekindles belief in the idea that the world can be made a better place through co-operation and mutual interests.”