Mark Thomas dispenses doorstep justice

When the state starts arresting people with iced cakes, it really is time to change the law, or for

Charles Kennedy is a recovering alcoholic. Mark Oaten has a predilection for rent-boy rough action. It has taken some time, but finally the Lib Dems are starting to behave like a proper political party. All we need is for Menzies Campbell to have a string of undeclared directorships and for Simon Hughes to have left his council tax unpaid for the past ten years, and the Lib Dems will have truly arrived.

The Lib Dems are being squeezed by David Cameron garnering support for the Tories and by the Labour supporters who voted Lib Dem in the last election returning to Labour next time round. They are doomed unless a leader of outstanding stature and charisma can be found. Who can lead them? Who can save them? There is only one hope for the Lib Dems - step forward London's bottle-nosed whale! The plucky whale is glamorous, adventurous, has a high public recognition factor, quite literally identifies with the floating voter and, being dead, has a dash of personal tragedy that makes him appealing to the lady electorate. Though should the whale decide to stand, a News of the World hack somewhere will be hunched over a phone listening to clicks and whistles before uttering, "What's that, Flip? . . . A rent dolphin, you say?"

And so from Liberal to the illiberal: Socpa, which, as readers are aware, is not the name of a criminal organisation bent on world domination in a 1970s TV spy thriller, but the acronym for the Serious Organised Crime and Police Act 2005. Readers will also know that this piece of legislation outlawing protest in Parliament Square was brought in to get rid of one man, Brian Haw, and the anti-war vigil he has kept for nearly five years.

That a government introduced a law to remove one man outside parliament was weird enough. However, Socpa criminalised protest in Parliament Square after the act became law, and because Haw's protest started before this, it did not apply to him. And so new Labour became authoritarian control freaks, and inept ones at that - the political algebra being Stalin + Frank Spencer = David Blunkett.

Under Socpa, two unauthorised protesters at the Cenotaph, Milan Rai and Maya Evans, were arrested for reading out the names of British soldiers killed in Iraq and attempting to ring a handbell. Evans was prosecuted at Bow Street magistrates' court. Yet the police have been far from consistent in applying the law, ignoring a protest at the Cenotaph only weeks later.

In Parliament Square recently, a banner reading "Parliament Square belongs to the people" was deemed a statement of fact and therefore not a protest. Barbara Tucker's banner, on the other hand, which declared "I am not the serious organised criminal", was deemed a protest and Tucker faces trial in February. Who knows, had she used the words "I am a flippant chaotic law-abider" the banner may have been legal. In August police arrested Mark Barrett for the crime of having a picnic in Parliament Square. Two weeks later five others were arrested in possession of cakes iced with the slogans such as "Peace " and "Love" in pink sugary letters. When the state is arresting people with iced cakes, it really is time either to change the law or for ministers to start incorporating khaki uniforms into their daywear.

There are organised picnics in Parliament Square every Sunday (1pm), but there is another way to challenge this law. Section 126 of Socpa deals with harassment, which occurs if "a person is present outside or in the vicinity" of anyone's home with the purpose of "persuading" them "not to do something he is entitled or required to do", or to "do something that he is not under any obligation to do". Basically, if someone turns up on your doorstep trying to persuade you to do something you don't want to do, they are breaking the law.

Labour has just criminalised trick-or-treaters. Their presence outside your home is to get you to give them chocolate. You are not obliged to give it. That, therefore, is harassment. Nick the kids and take their DNA! Carol singing, too, could become an illegal act - singing in a threatening manner. In fact, just trying to get you to celebrate Christmas is illegal, if it is done by someone on your doorstep. Think of the applications this law has. Picture the scene: you shouting at Jehovah's Witnesses on the doorstep, "I don't want to believe in heaven. This is harassment!"

The real prize, though, could come around election time. Canvassers, party workers and politicians who ask or encourage you to vote for their party could be breaking the law, if you don't want to vote for them. The mere presence of rosettes, balloons and possibly even battlebuses in the vicinity of your home could be an act of harassment. All right, it might be a tad far-fetched, but have a look at the act and see for yourself. In fact, it is worth getting a legal opinion on it. Any readers willing to help on this are welcome.

Hey, we might even start a fund for the court cases. What greater way could there be to re-energise public involvement in the political process than the prospect of getting a politician arrested for harassment?

We have Socpa, ID cards on the horizon, innocent people's DNA on police databases and a Freedom of Information Act that Charlie Falconer, the Lord Chancellor, whinges about because people have the audacity to ask too many questions. It is the state that should be explaining itself to us, not the other way round.