Katy Guest: Left vs right - it's a question of manners

Though it seemed impossible, a hitherto untouched minority group found itself condemned by the Daily Mail last week. The rest of the week's Mail hate figures were pretty orthodox: the PC Brigade; "slatternly C-list women celebrities"; Peaches Geldof ... But on Tuesday, the paper suddenly took against the readers of The Guardian. "Prattish ... corduroyed bores," it called them.

Naturally, the straight-talking heroes of political incorrectness who work at the Mail have no time for the tofu-munching yoghurt-knitters at The Guardian. Likewise, the socially aware intellectuals of Farringdon look down on the reactionary bigots in Kensington. But it is rare for one to direct its fury at the other's innocent readers.

But last week, a principle was at stake: blasphemy. Guardian readers had overstepped the mark: 80 per cent of them, according to a poll conducted by the paper, object to the idea of Margaret Thatcher having a state funeral. And when Guardian readers object to something, they're not slow to share it.

The backlash started relatively gently in The Guardian letters page. "I cannot believe that I am alone in feeling total disgust ..." began one reader. But of course he was not alone: for Guardian readers, disgust is a team sport. Soon, the messageboards were alive with the sound of principled indignation (it's a sort of huffing noise). Readers queued impatiently for their turn on the moral high ground. "I rather like the suggestion that whatever happens she is going to be buried at sea," wrote one, "because by the time everyone has finished pissing on her grave..." Drinking champagne was mentioned.

Obviously this could not go unchallenged. The Daily Mail launched holy war, in the form of Quentin Letts. "The letters page of The Guardian ... has this week descended to virulent venom," he wrote, completely misunderstanding the Guardian-reading mind. It takes huge commitment to maintain exactly the same level of impotent fury in the face of genocide, milk snatching, global warming or queue jumping in Fresh & Wild. This isn't venom: it's a full-time job.

Just ask Mail readers, who are the only people standing between us and hell in a handcart. "I can't even think of the real name of that so-called newspaper without feeling sick," emailed one. Stand by for the headline – Thinking of The Guardian gives you cancer.

The thing about being a leftie is how exhausting it is having to be right all the time. There's no time for manners when you're keeping the red flag flying and there's a line of chavs between you and the last organic muesli bar.

Each side has stood its ground in the past week, holding back their opposing waves of inevitable social breakdown. But now things have descended to the level of playground debate. "Left-wing Nazis," says one side. "Offensive bigots," counters the other. Children, please, stop bashing each other, admit you love each other and get a room.

The lefties, however, won't let it lie. So what if Lady T left office 18 years ago? But it's a long time for a sore to fester. Yet some people are more forgiving than others. Before the 1997 election, even Neil Kinnock admitted the lady wasn't all bad. You don't have to agree with him to rise above it. But you wouldn't be a Guardian reader if you didn't still have the champagne on ice.