Could Brexit be stopped after all? Pro-European hopes have been raised by the announcement that Best for Britain, the campaign group aiming to reverse the referendum result, are to launch a new manifesto and a new campaign to secure and win a referendum re-run before 30 March 2019 to prevent Brexit taking place.

Anti-Brexit campaigners face considerable hurdles, not least public opinion, which is essentially deadlocked between Leave and Remain, but even before they get to that battlefield they face a number of obstacles. Re-opening the Brexit question is opposed by major powerbrokers in both parties: in the Conservative Party, it is guaranteed by the party leadership out of necessity and a sizable faction of the backbenches out of conviction, and in the Labour Party, it’s the other way round.

But the continuing failure of the Conservative party to reach an accord that unites Conservative MPs, is capable of winning majority support in the House of Commons and is acceptable to the EU27 means that there is a small – albeit wafer-thin – chance of a referendum re-run before 30 March 2019.

But even if that date should come and go, a third referendum on the United Kingdom’s relationship with the European Union is all-but-inevitable, unless the EU itself collapses (which is not impossible, but not likely either). It’s easy to see the circumstances in which that referendum re-run could come about: a hung parliament in which pro-European MPs hold the balance of power, a small majority in which the prime minister is beholden to her pro-European backbenchers, or an outright victory by a party which unifies around a referendum as a way of getting through an election without its divisions coming to the fore. Put together, that at least one of these will happen in the coming decades is inevitable, which is why the matter of a referendum re-run is a question of when, not if.

What should worry pro-Europeans, however, is whether they will be in a fit state to fight and win that referendum when it happens.