The government may have broken the law with the EU referendum

The government failed to follow its own rules in the way it ran the Brexit referendum, according to a leading constitutional expert who said he agrees with a prominent Eurosceptic lawyer who raised the same point in the House of Commons.

Dr. Peter Catterall of the University of Westminster told Business Insider: "The government didn't actually do what it should have done in terms of the legislation."

Dr. Catterall says that under the European Referendum Act 2015 the government was required to present two documents to the population in the run-up to the vote: "One that sets out the benefits of membership and the other which sets out the alternatives to membership."

"The alternatives to membership, however, didn't actually spell out what the alternatives to membership in great detail," Dr. Catterall says. "What it did was spell out why none of these alternatives to membership are as good as what we've got at the moment. It's a perfectly reasonable thing to do, the problem is that's not quite what the legislation spelled out should happen."

The booklet that was meant to set out alternatives was titled: "Why the government believes that voting to remain in the EU is the best option for the UK" and let to accusations of bias from the Vote Leave campaign.

Eurosceptic lawyer and Conservative MP Sir William Cash raised the issue in the House of Commons in late February, saying: "On June 23 the people may not have impartial and accurate information. I believe the government is probably, if not certainly, in breach of their duty under section six and seven of the European Referendum Act 2015."

Dr. Catterall told BI: "Personally, I agree with him. I think the government did not comply with its obligations under the act. Legislation sets out the rules. In this instance, the government have not applied their own rules. I'm quite skeptical that they would apply their own rules in future."

Dr. Catterall writes in an as-yet-unpublished article on the matter seen by Business Insider that this booklet was "flawed as a way of informing its readership of those alternatives, not least because it concentrated more on the negatives of any of those alternatives, rather than how they might, in fact, be realised."

However, Dr. Catterall concedes that this breach of the rules will likely go unpunished unless someone decides to challenge it in the courts.

Dr. Catterall has also argued that there should legally be a second referendum to approve the contents of any eventual deal with the EU over Britain's withdrawal from the union. More than 1,000 prominent British lawyers have also signed a letter urging Prime Minister David Cameron to allow Parliament to decide whether the United Kingdom should leave the European Union.