Tony Blair is right – Brexiteers shouldn't be afraid to change their minds now it's clear what leaving really means

It's true that the mood could change when people realise the implications of 'Brexit at any cost'

Even some of his friends admit that Tony Blair is not the right man to lead the fight against the hard Brexit towards which the UK is sleepwalking. But Blair’s argument, in a speech in London on Friday, is right: the public should be given the chance to change their mind if they judge that the exit deal would damage the country. Someone had to say it, and someone with a voice big enough to be heard.

Significantly, Blair went further, admitting that his new “mission” was to actively persuade them to change their mind. Inevitably, his Europhobic enemies had already accused him of “undermining democracy” before he even opened his mouth, so he was honest about his real aim – to halt Brexit completely rather than just prevent a bad Brexit, which some former Remain campaigners regard as their best hope now.

Blair acknowledged that he might not succeed – and I wouldn’t put his chances much higher than very slim. At the moment, the public mood is to “get on with it”. But he was right to say that the mood could change when people realised the implications of “Brexit at any cost”. He is convinced people will eventually judge the pain not worth the gain, but believes the hardliners driving the Brexit process are deliberately closing off the options so that any such change of mind cannot happen in time to halt the juggernaut.

The former Prime Minister will be seen as an even more controversial figure after this speech. He is an easy target for the hardliners pushing Theresa May to the hard Brexit she does not deliberately seek but into which she may stumble.

Yet Blair’s argument was based on common sense; if any business realised that a proposed deal was turning into a disaster, it would walk away and stick with the safety of the status quo rather than go for an even worse alternative deal. That is what could happen if we get a bad offer from the EU or can’t reach agreement with it in the next two years, as we would end up trading with the EU through the tariff-based regime of the World Trade Organisation (WTO).

There is no public mandate for such a damaging outcome or a majority in Parliament for it. But the House of Commons proved spineless when it scrutinised the bill triggering exit negotiations under Article 50 of the Treaty on the European Union. The Labour leadership and the 30 pro-EU Conservative MPs were so frightened of being accused of ignoring the referendum that they declined to vote for what a majority of the Commons wants: the right to send May back to the negotiating table to improve her deal. Which is why we might end up with the default option of WTO tariffs even though most MPs believe that would be the worst option.

Blair was withering in his criticism of Jeremy Corbyn’s weak leadership on the issue, saying: “The debilitation of the Labour Party is the facilitator of Brexit.” But the pro-EU Tories are equally culpable: they melted quickly under pressure from the whips and Downing Street, who argued that that the bill provided an opportunity to end the Conservatives’ historic divide on Europe while skewering Labour and even hastening its demise.

We can only hope that the House of Lords will do a better job when it starts to debate the bill on Monday. Some members of the unelected chamber will feel constrained by the Commons’ decision to roll over. But peers should do what MPs should have done: demand the right for Parliament to reject May’s deal without having to swallow an even worse one via the WTO.

In the end, it will not be Blair’s new cross-party campaign, MPs or peers who decide whether Brexit can be avoided, but the public. The politicians opposed to it will need clear evidence that Leave voters have changed their minds; that a bad deal is on the table; that the economy is suffering and living standards are falling. That is not happening yet. It might not happen in time, or ever. But Blair is right to argue that we should not be trapped in a mad Brexit if it does.