My post yesterday on the No campaign's focus on the man who wasn't there has provoked a sharp reaction from the former Lib Dem leader Lord Ashdown.
"The personalisation of the No campaign is disgusting politics", he tells me before going on to condemn what he calls a combination of "Conservative Party money and the dinosaurs of Labour who are attacking the man holding the coalition together".
This follows the Climate Change Secretary Chris Huhne's warning on Newsnight last night that "gutter politics" and "downright lies" are damaging the coalition. He went on to say that "I am frankly shocked that coalition partners can stoop to a level of campaign that we have not seen in this country before". He was referring not to coded and not so coded attacks on Nick Clegg but the No campaign's claim that voting under AV would cost millions and that it would promote extremism.
Both men will have seen the latest poll - ICM for the Guardian - showing a dramatic 16% lead for the No campaign. It is just a poll and just one poll and, more than in most elections, turnout is the key to this contest. However, the trend in all polls has been no-wards.
If that is the result it will be one more reason for some Lib Dems to ask 'What are we getting for staying in the coalition?'
PS One or two of you have complained that I am focussing on the horse race rather than the substance of the referendum. Point taken.
More on this to come but, for now, I've been studying Professor John Curtice's analysis for the Political Studies Association of whether AV would make much of a difference. Having projected general election results since 1983 under AV his cautious answer is that it would make hung parliaments "a little more likely" and give a "modest boost" to the Liberal Democrats.
At the last election, for example, Curtice estimates that the Lib Dems would have got 80 seats not 57, the Tories would have got 20 fewer seats and Labour three fewer. This would still have led David Cameron to conclude that a Tory/Lib Dem Coalition was the only stable option. However, the alternative Lab/Lib Dem Coalition would have had an overall majority - 335 seats against the 315 they did get - which might have convinced some that a "progressive alternative" could have worked.
The one recent election outcome which could have been dramatically different and could have changed the country's political history was 1997 when Tony Blair would have got - at least if these calculations are right - a bigger landslide and, more importantly, the Lib Dems would have replaced the Conservatives as the second biggest party - getting 115 seats as against the Tories 70.
Update 12:10: Thanks to those who pointed out my schoolboy error. Curtice's study suggests that the Tories would have got 20 fewer seats under AV, not 20 extra seats as I originally said.
Update 13:08: Lord Ashdown has just gone much further. Whilst campaigning for a Yes vote in Bristol he challenged David Cameron to disassociate himself from what he called a "deeply and appalling personalised campaign":
"There are three questions for Mr Cameron. Will he now disassociate himself from a deeply personalised campaign of the sort no British prime minister of whatever party should be associated with? Secondly will he explain to us why the Conservative Party is now funding a campaign whose primary theme is to attack his main coalition partner? And thirdly if he wants to take a high-profile lead in this campaign let him do so in favour of a campaign on the basis of honesty and decency. I'd like to hear him make a commitment on that."
And here's the response from a No 10 spokesman:
(1) Will he now disassociate himself from a deeply personalised campaign of the sort no British prime minister of whatever party should be associated with?
The PM yesterday said: "I don't run the No campaign, I run the Conservative No campaign... I certainly don't condone any personal attacks on anyone in this campaign."
(2) Will he explain to us why the Conservative Party is now funding a campaign whose primary theme is to attack his main coalition partner?
As the PM made clear yesterday the Conservative Party is running its own NO to AV Campaign. This is focused on highlighting how unfair and unpopular the AV system is and why people should vote No; it is a system that is obscure, unfair and expensive and could mean that people who come third in elections end up winning. It is not attacking Nick Clegg.
(3) If he wants to take a high profile lead in this campaign let him do so in favour of a campaign on the basis of honesty and decency. I'd like to hear him make a commitment on that.
The prime minister is focused on making the argument against AV - it is a system that is obscure, unfair and expensive and could mean that people who come third in elections end up winning.