To cheer myself up this morning, I attended the launch of the No to AV campaign, which hopes – as its organiser, Matthew Elliott, put it – to defeat "Nick Clegg's referendum" on 5 May.

Much as I expected, it was an enjoyable shambles, with a big wheel (the alleged £250m cost of switching to AV) falling off the no wagon almost immediately. Patrick Wintour and Allegra Stratton usefully set the scene here.

Today's event was staged at County Hall, just opposite the Houses of Parliament and, by my calculation, the scene of Mrs Speaker Bercow's recent photoshoot in a sheet.

The event starred Lord Robert ("I'm not a politician") Winston, the former Labour MP Jane Kennedy and Elliott, the founder of the mouthy Taxpayers' Alliance, who derided the yes camp's claims to represent the "anti-politics vote". That's my role, he seemed to be saying.

I have not finally made up my mind about my vote on 5 May. My prejudice tends to favour the "if it ain't broke, don't fix it" school of constitutional reform, and I sometimes despair of the muddle-headed panic that has gripped the political classes, especially since the debacle over MPs' expenses.

Reform of the voting system is only one of the instant panaceas offered up by the usual mixture of idealists, rascals, innocents and opportunists.

Always beware of panaceas. There's no system that can't be made worse by a little well-meaning stupidity combined with high-minded opportunism.

I'm pretty sure that cutting 50 MPs out of the system and imposing perpetual boundary reform is not going to serve the country well. Having just come back from Ireland, where a major complaint of reformers is that TDs (MPs) spend too much time on campaigning for votes and favours in their constituencies, I am reinforced in that suspicion.

That should push me in the no camp's direction – not least since the AV deal cooked up between Clegg and David Cameron when negotiating the coalition (a classic form of closed doors political haggling, by the way) is a "miserable little compromise" (Clegg's own words a year ago) which pleases almost no one, especially not the diehard Electoral Reform Society (ERS) types who are nonetheless co-funding the yes campaign.

The yes camp expects the no to try to wrap the coalition's deepening unpopularity around their necks – correctly so, as Elliott's opening "Nick Clegg's referendum" remark confirms. Listening to a yes campaigner the other day, I heard him concede that they, too, will have to go negative at some stage – but much closer to the day.

That shouldn't be difficult, since the no campaign seems to be run and funded – Wintour established that they won't have to declare their sources until months after the event – by a gaggle of familiar Eurosceptics like Elliott and George Eustace, now a Tory MP. In Rodney Leach, they have a man who is a twofer, both a Euroscep and a climate change scep. Bonus point!

Today, the no camp complained that neither coalition partner put an AV referendum into their manifesto (although Labour did) and that it will produce what Professor Vernon ("Bogbrush") Bogdanor warns is a windowless House of Commons where parties stitch up deals after the election.

This is exactly what happens in Dublin, so Irish reporters told me last week. No one takes manifestos very literally.

"Costly, unfair and a politicians' fix," was how Kennedy put it – and so do the no camp's fliers. They are planning rallies all over Britain. Alas, their own £250m costings, notably the back-of-an-envelope claim that Britain would have to spend £130m on voting machines, soon came unstuck.

Ministers have been coy about the costs of the referendum and of AV, if it wins, but the yes camp quickly hit back. There are no plans to introduce US-style voting machines, and Australia – which has used the system for decades – does not use machines.

"Desperate no campaign claims unravel," cried the instant press release. I agree with Lord Winston, who said this is all a bit rushed and that we need better public education on the pros and cons.

Where I currently think the yes camp has a case is in acknowledging that voters don't want to vote Labour or Tory in the 95% proportions they once did. They want to vote Lib Dem, Green, Ukip, SNP, BNP, etc, in larger numbers.

Might AV give more space for smaller parties to expand? I asked the no panel. Actually, it might give them less, but Kennedy told me no one had ever asked her for AV and that people can vote how they like.

Elliott said the Lib Dems have 11% of Commons seats but, currently, only 8% of some opinion polls. I call that a shabby answer, but I am sure he will do better next time.

Two niggles currently trouble me on the yes campaign's central claim that AV will be fairer, though not perfect. Everyone admits that the system whereby second choices of defeated candidates are transferred until someone has more than 50% can lead to less "fair" results.

In Ireland last week, I was reminded that, even under the PR lobby's Holy Grail system, the single transferable vote, odd things can happen.

Thus in 2002, Fianna Fáil won re-election with 41.5% of the vote – roughly what a Blair or Thatcher needed to get a majority – yet won 49% of the seats, the winner's bonus, as it is known. You could say that's still better that a landslide, but it's not strictly fair either. With two TDs short of a majority – 83 seats in a 166-seat Dail (remember, the Speaker is neutral) – FF ruled on with the help of micro-parties.

A different sort of wrinkle emerged in the then taoiseach Bertie Ahern's four-TD seat of Dublin Central in the 2007 election. So popular was Ahern then (he couldn't win a raffle now, thanks to the crash) that his surplus votes – those above the quota number he needed to win – were, when transferred, enough to elect his FF running mate, Cyprian Brady, as the fourth TD.

And how many first preference votes did Brady get? He got 939 against popular Bertie's 12,734. Seven other candidates got more, but only two got elected. Bertie carried his man across the line.

Well, those are the rules, and people elected by the rules are properly elected. But it does serve to remind open-minded voters that "fair" is a flexible word.

Fair to whom? By changing the rules, Clegg expects it to be fairer to centrists like himself. Voters may want that, and he may win the reform he seeks. There again, by 5 May they may want to vote against anything he wants. It's too soon to say.