So will the revolution start in Haltemprice and Howden?

It is no Runnymede. But Haltemprice and Howden is where the Magna Carta is destined to be defended some 800 years after it was signed.

Tomorrow is the anniversary of the day, in 1215, when the King of England appended his royal seal to an agreement with his rebellious barons which has since been held to be the founding document of English liberty. So much so that, as Tony Benn reached to communicate the significance of the vote to allow the imprisonment of terrorist subjects for 42 days without trial, he lighted upon that great charter as his historical reference. "I never thought I would be in the House of Commons on the day Magna Carta was repealed," he said.

King John and barons met in that picturesque meadow called Runnymede between Windsor and Staines on the 15th day of June in the 17th year of his reign. Haltemprice and Howden 2008 does not have quite the same resonance.

The constituency of David Davis, the former Tory shadow home secretary, who is going to resign his seat to fight a by-election over the 42-day controversy, is set in the flat featureless countryside of the East Riding of Yorkshire between the comfortable middle class suburbs of western Hull and the dull industrial canal town of Goole – a town once described by a local councillor as "the arsehole of the universe". (The description so outraged The Goole Times that it splashed the quote across the front page, delicately and more concisely recasting the words as "Goole: anus of the world".)

Such an epithet, however, would ill-befit the charming little market town of Howden (population 3,810) at the heart of Mr Davis's political homeland. Its architecture is Georgian, though the winding narrow streets betray the medieval origin of the town. The minster church was begun in 1228, two decades after the same King John granted the town the right hold an annual fair.

A fair, by the market cross in the centre of the town yesterday, was an altogether more modest affair. A trestle table selling plants stood by a stall covered with homemade cakes and scones and local free-range eggs, hen and goose. Inside the Shire Hall were stalls selling jewellery and hardware. Lorna Storey, who was running the jewellery stall, offered her support to Mr Davis. "I'm in favour of 42 days, but he gives support to things locally, so I'll support him," she said.

Across the road, two old ladies were discussing the news that had set the town abuzz. One in her eighties was leaning on a bicycle. "I'll vote for him," said the contender for the title of Howden's oldest cyclist.

"I won't," said the second.

"Who else is there to vote for?" asked a third, a mere youngster in her seventies, joining them.

The Liberal Democrats, who came second at the last election, had announced they would not field a candidate since they agree with Mr Davis on the 42 days. And there was talk of Labour boycotting what Gordon Brown described yesterday as Mr Davis's "stunt that has become a farce".

The only potential opponent so far was Kelvin MacKenzie, the former editor of The Sun, who that morning had indicated he might stand. "Really," said the third lady. "I'm a Sun reader, though we get the Yorkshire Post too. But I think I'll stick with David Davis. I don't agree with him on 42 days but he's done such a lot for the area even though it's a totally unnecessary election."

"Yes," said one of the others. "I just can't get my head round what he's up to."

On that, she was united with almost every other resident of the town. Whatever their politics they had that in common. "My politics are Labour," said the lady selling the bizzy lizzies. "I just don't understand why he's done it at all because, at the end of the day, the majority of people feel that 42 days is right. We've all got human rights, including the right not to be blown up."

The elderly man sitting on a foldaway picnic chair with a collecting tin for the Salvation Army was mystified too. "I'm amazed he's done it as the opinion polls show he's on to a loser," he said. "There are far more serious issues he could have resigned over. I'm inclined to spoil my ballot paper."

The lady selling the homemade Bakewell tart and apricot crumble cake was a Liberal Democrat. "Labour have ridden roughshod over liberties. And though his gesture is a bit futile – as a bloke he's vain and a bit up himself – I'll have to vote for him because I don't believe in not voting."

Only a portly Tory supporter at the hardware stall coincided closely with David Davis's line. "To me, 42 days is totally wrong," he boomed. "They're doing away with our freedoms. It's a sledgehammer to crack a nut. Anyway, he added, somewhat spoiling his Shami Chakrabati impression, "they can always find something to arrest these terrorist suspect for, even if it is inducing them to assault a police officer".

What was clear was that it was hard for many people to see the coming by-election as the single issue referendum which Mr Davis has proclaimed it to be. But then Magna Carta itself wasn't quite as straightforward as it is usually portrayed. The document which is popularly presented as the cornerstone of the nation's liberty was less of an iconic declaration of political principle than a pragmatic solution to a political crisis.

Feudal monarchs were entitled to ask the barons for men and money for their wars but King John had asked for too much. The barons rebelled. But for all its fine words – "no free man shall be seized or imprisoned, or stripped of his rights or possessions, or outlawed or exiled, nor will we proceed with force against him, except by the lawful judgement of his equals or by the law of the land" – Magna Carta is essentially a peace treaty by which the king promised to remit unjust fines, restore seized lands, promised not to force towns to make bridges over rivers, and much else.

None of that stopped Magna Carta entering the political imagination. The Levellers, the Chartists and many others embraced what they thought it said for their own ends, as Tony Benn has admitted in his less purple moments: "Magna Carta is sometimes spoken of as the birthplace of democracy. It's actually rubbish. Magna Carta was a struggle between the king and the landowners, it had nothing to do with the people, the people were entirely excluded".

Still a king had acknowledged, for the first time, that the monarch was subject to the law. And philosophers might argue that liberty is indivisible. Godfrey Bloom certainly does. At a previous election he stood against David Davis for the United Kingdom Independence Party. He is now the MEP for the area. He lives in the village of Wressle, near a ruined castle built by a baronial family in the century after Magna Carta.

He, too, lives in a different era, referring to himself as Godders, speaking of sharing "the occasional sherbert" with Mr Davis, whom he describes as "not unsimpatico".

"I welcome David's conversion to the issue of the erosion of liberties," he said. "Now he needs to acknowledge that the greatest source of that erosion is our surrender of rights to the EU ..." and he was off on a breath-defying diatribe against the evils of Europe. "If he extends his understanding of the threat to civil liberties, I'll be out there delivering leaflets for him. If he remains selective, I may have to stand against him."

Even Godders, however, accepts that Mr Davis will win – "probably on a low turnout but with a monster majority". But, like the folk in the market square, he suspects that the MP's career is over. "The whole by-election could become a silly season jape. That's the risk he's taken and it may come back to bite him on the bum."

"He won't get back in the Shadow Cabinet," said a Mr Davis supporter at the hardware stall. "He's thrown his career away."

"It's a pointless gesture," said the cake lady.

"He's probably finished in politics now," said the Sally Army man.

Shakespeare, who saw Magna Carta not as a triumph for liberty but rather as a shameful attempt to weaken the monarchy, offered a phrase for it in his play King John: "So foul a sky shall not clear without a storm".

The storm is beginning to break over David Davis's head, so I went to his aged-brick converted farmhouse home in the constituency to ask him how he was coping with what was being said by the locals.

"You're on my property, you're invading my privacy," he snapped irascibly when he came to the door. "Make an appointment before you come here." Quite what else an experienced politician expected after such a dramatic gesture was unclear. But then nobody said it would be easy being a guardian of liberty.