The organisation making the case for a No vote in May's referendum on voting reform has launched a series of adverts that are desperate and cynical in equal measure. These adverts focus on the supposed cost of the transition to the Alternative Vote system. The campaign asserts that the bill would be £250m and that "our country can't afford it".

Yet that figure is entirely spurious. It apparently includes the £82m that will be spent on the referendum regardless of the outcome and £130m for the purchase of electronic vote-counting machines. The problem with this line of argument is that no new vote-counting machines will, in fact, be needed. Votes would continue to be counted by hand, as they are at present. It displays a staggering disregard for honesty for the No campaign to rely so heavily on this confected figure.

Just as shameless is the implication of the No camp's adverts that a No vote will mean more money for public services. Voting no would apparently mean, according to the campaign's adverts, a state loan for the Forgemasters steel plant in Sheffield, flakjackets for our soldiers, and, most emotively of all, cardiac equipment for sick babies.

Even if one were to accept the No camp's figures for the transition costs to AV, it is disingenuous of them to suggest that these public goods would be safeguarded by a No vote. Some members of the Labour old guard such as David Blunkett and Margaret Beckett have lined up in the No camp (despite Labour backing a move to AV in its election manifesto last year). But Conservatives MPs are the dominant supporters of the No camp in Parliament. And Conservatives are also the strongest supporters of the Coalition's drastic public spending cuts.

The hypocrisy is not confined to elected politicians. The chief of the No campaign, Matthew Elliot, is the former head of the right-wing pressure group the Taxpayers' Alliance. It is ironic, to put it mildly, to see such a figure now posing as a protector of public spending.

Two other arguments have been deployed by the No campaign. It argues that AV makes elections "unfair" because the candidate who comes third can "steal" the election. It would be technically possible for a candidate who comes third in first preferences to prevail, but it would not be common. And this argument ignores the glaring injustices in the first-past-the-post system, such as the fact that though Labour and the Conservatives combined only managed to attract two-thirds of the votes in the general election last year, they ended up with almost 90 per cent of the seats in the House of Commons.

The No campaign also argues that AV will lead to more hung parliaments. Yet the example of AV in Australia plainly contradicts that. And as our own history attests, first-past-the-post can be just as capable of delivering inconclusive election results. There are serious arguments that the No camp could have put forward against AV, such as that it is not a proportional system, or that it can have the effect of enhancing a single party's Commons representation after landslide victories. It could have pointed out that many seats would still remain uncompetitive under AV. These arguments are hardly overwhelming, but at least they do not mislead people.

Instead the No campaign has chosen fear-mongering and deception. They appear to subscribe to the view that no one ever lost a campaign by underestimating the intelligence of the public. They always deserved to lose because of the weakness of their argument. Now they deserve to lose, too, because of the dishonesty of their campaign.