Tony Blair has issued a rallying cry to Remain voters to persuade Brexit supporters that Britain is better off staying in the European Union, telling them to "prise apart the alliance that gave us Brexit".
The former prime minister said the will of the people should be respected, but insisted Remain voters "have to believe in the people's innate sense, that they're also open to a better argument in the light of the facts as they come to light".
Describing Remain voters as the new "insurgents", Mr Blair said as the "catastrophic" realities of leaving take hold, staying in must remain an option.
Worries about future
He highlighted the sharp fall in the pound as a "negative prediction about our economic future", and the blocking of a Canada-EU free trade deal by the Walloon regional parliament in Belgium as evidence that Brexit may not take the form many Leave voters had imagined.
Writing in the New European newspaper, Mr Blair said: "The issue is not whether we ignore the will of the people, but whether, as information becomes available, and facts take the place of claims, the 'will' of the people shifts.
"Maybe it won't, in which case people like me will have to accept it.
"But surely we are entitled to try to persuade, to make the argument, and not to be whipped into line to support a decision we genuinely believe is a catastrophe for the country we love."
Staying in EU 'should remain an option'
He said Remain voters must win the argument that staying in the EU should stay on the table, warning that anger and anxiety about immigration, globalisation, stagnant incomes, housing and squeezed public services will only get worse outside the EU.
"Right now there is one point and one point only to win: we should keep every option open," Mr Blair wrote.
"That this should even be contentious speaks loudly about how much those of us - and after all we were 16 million people - who believe Britain's future lies within the European partnership, have been shoved on to the defensive.
"We have to respect that people voted as they did. But we have to believe in the people's innate sense, that they're also open to a better argument in the light of the facts as they come to light.
"We have to recognise we're the insurgents now. We have to build the capability to mobilise and to organise.
"We have to prise apart the alliance which gave us Brexit.
"We can make up our mind; and we can change our mind. And whether we do, is up to us."