We now know the Electoral Commission believes that Vote Leave, the “official” leave campaign, broke the law. This comes in the wake of its conclusion that Arron Banks’s Leave EU broke the law. But what does this actually mean – for the referendum and our democracy?

Back in February 2016 – while lobbying for Vote Leave to be recognised as the designated leave campaign – Steve Baker MP (now a minister in the Department for Exiting the EU) wrote of a loophole he believed he had uncovered. The “designated campaign will be permitted to spend £7 million,” he said. But he also added: “It is open to the Vote Leave family to create separate legal entities, each of which could spend £700,000: Vote Leave will be able to spend as much money as is necessary to win the referendum.”

The Electoral Commission ignored this alarming indication of an intention to game the spending caps set down by parliament, and awarded this campaign official designation and £600,000 of public money.

Vote Leave “donated” £625,000 of money or advertising to an obscure fashion student in Brighton, and a further £100,000 to an organisation called Veterans for Britain. They subsequently spent this £725,000 – together with a huge chunk of Vote Leave’s £7m – with a then obscure internet advertising firm based above an optician’s in British Columbia, Canada. The Electoral Commission took a cursory look at this and concluded that there was no wrongdoing. But the Good Law Project, which I set up, sued. The Electoral Commission consequently agreed to reopen its investigation. Thanks to Matthew Elliott, the former chief executive of Vote Leave who chose to release the details of the accusations the commission has made against it (in an attempt to pre-emptively challenge and perhaps neuter their impact) we now know it has written to Vote Leave stating it believes it broke the law.

The immediate consequences of that finding are legal. There should be fines for Vote Leave, and there could well be criminal charges to follow.

But an even bigger question is what this means for the referendum result, and the future of our democracy. In 2015, parliament debated whether the EU referendum needed legal safeguards. It eventually went on to jettison a series of legal rules that normally apply to safeguard votes from cheating. The sad consequence is that – although a judge may yet join the Electoral Commission in deciding Vote Leave broke the law – there is unlikely to be any way in which a court might declare the outcome void.

Parliament instead left to MPs the job of choosing what to do with the referendum, which government ministers made clear was “advisory”. And in normal times, where they acted rationally and on the basis of evidence, this would be enough: it is beyond sensible doubt that there is no proper mandate to leave the EU. The notes to the Venice Commission on referendums, to which the UK is a signatory, says “if the cap on spending is exceeded by a significant margin, the vote must be annulled”. Our own courts have said: “In elections, as in sport, those who win by cheating have not properly won and are disqualified.” The rules that parliament decreed to ensure the referendum was not captured by oligarchs will have been breached.

The fact nobody can prove beyond doubt that Vote Leave’s cheating made the difference is beside the point. Did we say to Lance Armstrong’s seven runners-up, “Yes, we know he’s a drugs cheat but can you prove you would have won if he hadn’t taken drugs?” Of course not – how could they prove that?

There are also serious questions about how much Michael Gove knew about these arrangements. In an interview in March, he denied being involved in the day-to-day running of the campaign. But Vote Leave’s own documents record that he, along with Boris Johnson and Matthew Elliott, “meet on a daily basis … to ensure that the campaign is on track”. Is his case that, despite these daily meetings, he did not know of or approve how over 10% of Vote Leave’s cap was used?

Ultimately these are questions for MPs, as they should be in a functioning democracy. But if they once felt shackled by what they were told was the will of the people, those shackles should now be well and truly off.

• Jolyon Maugham QC is a barrister and director of the Good Law Project