For all of his many faults, Nigel Farage has shown himself, in the course of his 20 years as a professional politician, to have some insight into the mood of the British public. It pains me to concede it but he has shown that instinct for populism again today by calling for a second referendum. Of course, Farage believes that a second vote will vindicate him and his hard Brexit comrades. He is asking not for a plebiscite so much as some sort of reckoning, with violent language to boot (he said: “I think that if we had a second referendum on EU membership we would kill it off for a generation”). But the underlying argument he makes is essentially correct – Brexit is not a done deal, the future is still up for grabs and the debate about Britain’s place in the world continues.

Nigel Farage backs fresh Brexit referendum to 'kill off' issue Read more

We advocates of Britain’s European future must now do two things. We should welcome this concession from the Ukip establishment that a single referendum does not, after all, mark the beginning and the end of this debate. And we must prepare ourselves for the fight of our lives. I believe that a second vote can be won – handsomely – by a movement for a fairer and more democratic Britain within the EU. We can win. But it is not inevitable. We cannot threaten or pronounce our way to victory. Instead we have to go out into the country and answer the crucial question for many who voted to Brexit out of legitimate anger and despair: If not leave, what? What can we do to give people security, esteem and optimism so that they can view a European Britain – with all the opportunity that brings – with confidence and enthusiasm?

Play Video 0:44 Nigel Farage backs second referendum on Brexit – video

Given that Nigel Farage is this country’s de facto prime minister – pulling the strings of a weak and directionless prime minister – we can expect a second referendum to become government policy in no time at all. This time there must be no room for excuses or for complacency. We won’t win unless we deserve to, unless we show voters that we have listened and we have learned and that their howl of anger is not being ignored. That has to be every “remoaner’s” mission from now on.

• Andrew Adonis is a Labour peer and former cabinet minister