Arron Banks, the UKIP donor and co-founder of Leave.EU, was never likely to stay quiet for long. In late September, after various very public mishaps, he declared that “Twitter [is] clearly above my paygrade” and fell silent. A few days ago, though, he resurfaced.

Why return to public commentary now? Well, that soon became clear – yesterday a letter was released in which Banks proposed to Matthew Elliott, founder of Vote Leave, that the two anti-EU campaigns should join forces.

The timing is interesting. In recent weeks, Nigel Farage has subtly shifted his tone from enthusiastic support for Banks’ campaign alone, via warmer words about both groups, and now to a more qualified insistence that “all anti-EU voices must come together”.

At the same time, experienced Eurosceptic campaigners point to the contrast between the two organisations. We reported in September on their very different operations. Concerns remain that Leave.EU’s campaign team lacks depth and experience in the field, leavened though it is with American consultants Goddard Gunster, and the campaign continues to pile up Facebook likes, despite their questionable value, while Vote Leave has a lower social media profile but a growing team of experienced campaigners.

The difference behind the scenes is starting to show in their respective performances, too. While Banks has secured the bulk of his headlines by attacking other eurosceptics (memorably calling Douglas Carswell “borderline autistic with mental illness wrapped in”, for example), it is the Elliott/Cummings group which has made the political running on the referendum itself. Vote Leave has run a hard-hitting campaign to blunt the CBI as a pro-EU force, and worked with its allies in the Parliamentary Conservative Party to secure and seek to enforce a pledge that CCHQ will remain neutral in the referendum.

Naturally, Banks dismisses such work as ‘Westminster bubble politics’, the irrelevant power plays of insiders. But such battles matter, in that they establish the very terms of the referendum campaign: the pro-EU campaign would undoubtedly be more powerful if the machinery and money of the CBI and the Conservative Party was ranged freely behind it. Acting early to cut the Remain campaign’s lines of supply is canny campaigning.

It is both easy and fashionable to sneer at people with a background in political campaigns, but Vote Leave know what they are doing and – for the most part – they do it well. Banks has fallen prey to the seductive fantasy that being good at business automatically makes him good at politics – despite the history books being strewn with others who have made the same mistake. Tellingly, that view is shared in some senior UKIP circles, too – I’m told they became increasingly alarmed at the way their donor set about using his newfound public platform, and that concern contributed to Farage’s shift away from his unqualified support for Banks.

It is clear which of the two campaigns has hit the ground running – indeed, attempts by Eric Pickles to prevent Vote Leave securing official status speak volumes about the organisation’s progress. But that isn’t to say that the Leavers shouldn’t consider unifying. Banks is surely right to argue that duplication – particularly of costly overheads – is wasteful, and the division has offered the BBC and other pro-EU journalists unnecessary opportunities to land punches.

The essential question is on what basis and on what terms an alliance or merger could be established.

The groups differ on their preferred strategy and messaging – but that isn’t insuperable. It’s perfectly possible to imagine Leave.EU focusing on a Get Out The Vote operation among convinced anti-EU voters, while Vote Leave pursues the more subtle challenge of convincing floating voters, for example. Or, for that matter, there’s nothing to stop one subscribing to the strategy of the other if they were to undergo a change of heart.

Nor are partisan barriers a real problem. There are people of all parties supporting each group as it stands, and Farage’s hostile rhetoric about Vote Leave (he once ascribed Carswell’s support for Vote Leave to “residual loyalty to his old friends in the Tory party”) has softened somewhat – though he still apparently discourages his MEPs from co-operating fully with non-UKIP campaigners. Any Leave campaign must be a cross-party effort if it hopes to win the eventual referendum, and there are very few eurosceptics who fail to recognise that fact.

Rather, the main obstacle to unification or alliance between the two Leave campaigns is Arron Banks himself. While his enthusiasm for public insults has of course annoyed some of those targeted (including various of the campaigners and politicians he now seeks a merger with), he has a much more serious problem: the key eurosceptic donors who will fund the Leave campaign do not feel they can work with him.

Those putting sizeable sums of money behind a cause they deeply believe in understandably want to know that those funds will be used responsibly, the campaign will be carried out with good judgement and that those involved can be trusted. In a few short weeks as a campaigner, Banks has convinced the main Leave donors that he does not meet any of those conditions. There are other senior people in Leave.EU with whom they believe they can do business, but Banks himself has become a sticking point.

In his letter proposing talks, Banks promised that there would be “no prior conditions”, meaning that nothing is off the table. If that really is the case, then there could be a chance of reaching an agreement. It would require him to put the interests of the nation ahead of those of the individual – Banks would have to recognise that the essential pre-condition to achieving a deal (and thereby to improving the chances of a Leave victory) is for him to step aside from a leadership role in the campaign. Only time will tell if he can bring himself to do so.