‘Next year it will be the 800th anniversary of Magna Carta. Indeed, it was on this very day, 799 years ago, that the Great Charter was sealed at Runnymede in Surrey. 

It’s a great document in our history – what my favourite book, Our Island Story, describes as the ‘foundation of all our laws and liberties’. 

In sealing it, King John had  to accept that his subjects were citizens – for the first time giving them rights, protections and security.’

So wrote David Cameron in the Mail on Sunday three days ago. He was right to emphasise the importance of history to understanding British freedom – and to suggest that schools could do worse than promote the values of liberty before the law which were wrestled into being in these islands over the course of a thousand years.

Thus far, the debate has focused on whether such values exist, and, if they do, whether they should be taught in school. But we should also ask whether, while celebrating the values that set us free, the Government itself lives by them.

Take one of the longest-lasting principles established by Magna Carta – the protection from being punished unless one has been found guilty in a court of law:

No Freeman shall be taken or imprisoned, or be disseised of his Freehold, or Liberties, or free Customs, or be outlawed, or exiled, or any other wise destroyed; nor will We not pass upon him, nor condemn him, but by lawful judgment of his Peers, or by the Law of the land.’

It only requires a little bit of translation – ‘disseised’ means deprived, or dispossessed. In short, it’s the simple statement that your property and your liberty can only be taken from you if properly convicted.

In fact, H.E.Marshall’s ‘Our Island Story – cited by the Prime Minister in his article as his “favourite book” – comments on it like so:

‘These things seem to us now quite natural and right, so you can imagine what evil times these were when the King was unwilling to grant such liberty to his people.’

What evil times indeed.

And yet it seems the Downing Street copy of Our Island Story might be missing that page. 799 years on from Runnymede, the Government proposes to directly contradict this principle.

HMRC is set to gain a raft of new powers to take money which it deems to be owed directly from individuals’ bank accounts, and to demand disputed tax payments from alleged aggressive avoiders up-front with little to no opportunity to appeal. If you explained the proposals to someone from 1215, they’d recognise an attempt to “disseise” people of their property without trial, plain and simple.

Those who don’t pay their taxes are an unsympathetic group of victims. That is why we have heard remarkably few objections in Westminster to these ideas – who wants to be painted as a defender of those who don’t pay their fair share?

But it would be a grave mistake to accept such new powers on that basis.

For a start, freedom before the law only works if it is equal – we offer even the most blatantly guilty mugger the chance of a fair trial, for all our sakes. Start tearing away freedom from the worst and soon it will be stripped from us all.

Just as importantly, HMRC has form for wrongly deciding that people owe tax when in fact they do not. In recent years, it has miscalculated the income tax of millions upon millions of people, landing some with unexpected bills and others with refunds (and some – like me – with the brief joy of a refund letter only to be followed by a bill for almost exactly the same amount the next day).

Making any public body “judge and jury”, as the Law Society described the plans, is a bad idea – giving such power to a public body famed for its incompetence is a disaster waiting to happen.

We can all understand the Government’s wish to ensure that unpaid tax is collected. We can all understand their wish to ensure it is collected more swiftly, too. But short term fiscal goals are not a good enough reason to override what the Institute of Chartered Accountants rightly believes to be:

“a fundamental tenet of our English law and our democratic society” that money “cannot be grabbed from somebody’s account without a judge agreeing to the move”.

The accountants know it. The Prime Minister’s favourite author knew it. The barons facing down King John intended it to be so.

If, when planning the commemoration celebrations for Magna Carta’s 800th anniversary, David Cameron really believes that “its principles shine as brightly as ever”, maybe he should honour its memory by governing in accordance with those principles. What better way to honour and teach British values than by putting them into practice?