Let us start with the Green candidate in last year's Norwich North by-election, Rupert Read, who would like to show you a Lib Dem leaflet.
Headed "Residents shocked by Green Party candidate's terror views", it says: "Little is known about Rupert Read, but one thing is certain, local people have taken against his extreme views." Dr Read, said the flyer, believed that "Britain simply had the terrorist attacks on 7 July coming to us". One safely anonymous "local resident" was then quoted as saying: "What planet is he on?" Another, equally shy, "Norwich resident" opined: "I can't believe that anyone could think that."
The voters of Norwich would have been right not to believe it, since it was a wholesale distortion of something Dr Read had written, four years earlier, equating terrorism with acts such as the Iraq war, but very clearly condemning both and calling for an "ethic of non-violence", as practised by Martin Luther King and Gandhi.
"It had some quite unpleasant consequences for me," says Dr Read, a philosophy lecturer. "The whole Liberal Democrat campaign was sickening. I look now at Nick Clegg promising to clean up politics and I remember that he was specifically asked to criticise his party's tactics in Norwich, and he refused."
At the current and Euro elections, according to Dr Read, local Lib Dems have distributed leaflets printed in green, resembling Green Party literature, saying the Greens have no chance (actually, it is the main opposition party on the city council) and calling on their supporters to vote Lib Dem. In Tory areas, they have sent out leaflets printed in blue ink, saying the same about the Tories (who in fact hold the seat).
"People were telling me on the doorstep: 'I got your leaflet telling me to vote Lib Dem, so that's what I'm doing'," says Dr Read. "Anyone who's in politics knows that the Liberal Democrats are the dirtiest in their campaigning techniques, and I'm saying that as a former Lib Dem. It's one of the reasons I left."
I defended Nick Clegg yesterday against what looked like a concerted campaign to undermine him. What a pity Mr Clegg presides over a party which is quite happy to use deliberate smears against its opponents. The clean party of British politics? Don't make me laugh.
UPDATE: And today they're at it again! Click HERE to read how a LibDem staff member posed as a nurse in an election leaflet. Imagine for a moment their reaction if the Labour or Conservative Party had done this.