The Conservative MP whose name I missed, Mary something or other, made the worst mistake a by-election pundit can make speaking on the BBC News 24 from the Felham and Heston count. That is second guessing the electorate after the polls have closed. Either that or maths might not be her strong suit.

She claimed that the swing to Labour would not be significant, but didn’t challenge the claim by Fiona Mactaggart MP that Labour would increase it’s majority on half the (woeful) General Election turnout. For both to be true would be a virtual impossibility.

In the event a swing of 8.6% to Labour is large for a relatively safe Labour defence at a by-election – and certainly ‘significant’. The movement was not as spectacular as at Barnsley, but still credible. In effect Labour trebled its majority in percentage terms. Relative movements are also important to consider when crunching by-election numbers. Labour’s share of the vote sat roughly halfway between its level in the 2005 and 1997 elections. In Barnsley Labour got closer to it 1997 level, but it had in the meantime fallen much further. So not bad.

Speculation from by-election results is largely pointless. The Conservatives may feel some crumb of comfort in the fact they they didn’t get quite the hiding that they got at Barnsley, but it should be remembered that Feltham and Heston was a Tory seat in both 1983 and 1997. They also had the gumption to field a candidate who had fought the seat several times in the past and therefore had some local loyalty.

Wherever the Tories are right now it is probably not in landslide territory. As for the Liberal Democrats the pointlessness of their presence was clear for all to see, but this time although their share of the vote was more than halved remaining just ahead of UKIP. The party that once stormed to victory at by-elections now celebrates saving its deposit.

The LibDems beating UKIP was probably to do with the Tories losing fewer votes to the Europhobes as a result of Mr Cameron’s ‘non-veto veto’ and, perhaps, gaining a few from the Tory centre on the same issue. However in this strange political week it is worth pointing out that pro-EU parties (by reputation if not by recent actions) polled around 63% while anti-EU parties managed around 37% between them. There is little real evidence that the EU curfuffle cost Labour votes in just the sort of place that it might. Whatever else, it is fair to any effect on electoral fortunes of the PM’s lunacy will be short term which may not be the case for the effect on the economy.

Finally, It’s worth congratulating Labour’s Seema Malhotra, an obviously bright woman who could go far.

* Apologies to readers for a few more typos than normal in my first draft – I’m putting it down to using an iPad touch screen thing with a will of its own.