If the central message of your referendum campaign consists of two lies you have a problem.

The picture above shows the Vote Leave battle bus, with Boris Johnson standing in front of it. The message is clear. We send the EU £350m a week and we should use that money to fund the NHS instead. Here’s the problem, the first half of this sentence is a straight lie and the second half of this sentence is an ideological lie. No wonder Vote Leave have been trying to move their campaign onto immigration – because having this message as the center of their campaign, as it was for over a month – says something about their desperation.

Let’s start with why the figure is a lie. We DO send £350m a week to the EU, totaling about £18bn, but that is a GROSS figure. We get money back, and so the NET figure is at most half of it and some say down to a third. But the battle bus suggests that the £350m IS a net figure. Andrew Dilnot, Chair of the UK Statistics Authority, says that the use of this figure is “misleading and undermines trust in official statistics.”

From the £18bn, we get a rebate of about £4.5bn a year back – and then we get payments from the EU to Britain to various areas like agriculture and university science which total about £4.5bn. Those figures coming back can be greater. So the true figure we send to the EU is about £9bn.

Daniel Hannan, a prominent Vote Leave campaigner, dismisses this net figure. He likens it to council tax, saying that we pay council tax and we get services back but we don’t then say that our council tax contribution is half of what we actually pay. But this is a specious argument, because what we get back from council tax is in services but what we get back from our Budget contribution is in actual money.

When this was put to a Vote Leave spokesperson she said that the problem is that the budget contribution – the money going out, is in the EU Treaties, so whatever happens we would HAVE to spend that money, but the money coming back in terms of the rebate is simply the result of a negotiation by Margaret Thatcher that could be overturned at any time and the money we get back from the EU in funding for agriculture etc is uncertain and more importantly the EU chooses where it goes not us.

Ok, so let’s take those arguments and let’s live in an imaginary world where we accept that we do, indeed, send £350m a week to the EU that we wouldn’t have to spend if we left and so we could spend on other priorities, like, the bus says, the NHS.

Have a look at the politicians who back the Vote Leave campaign. Have a look at the ideological backgrounds of those that fund it. Do you seriously think any of them would actually spend a penny of that £350m a week on the NHS? Many of them are Libertarians, so would simply want to reduce the tax burden. Many of them are right-wing Tories, wary of the size of the state. Nigel Farage talked of paying for the NHS through insurance as recently as 2012. Former PM John Major put it best when he said that trusting the likes of Johnson, Gove and Duncan-Smith with the NHS is like trusting a pet hamster with a hungry python.” Most of the Vote Leave campaign would far sooner spend that £19bn on new fighter planes and aircraft carriers than they would the NHS. So that’s the second lie.

I’ve not even addressed the fact that many of the countries outside the EU but with free trade agreements with it – like Norway – STILL contribute to the EU budget. I’ve also not addressed the benefits we get from being members of the EU such as gains from trade with it in terms of exports and jobs.

That’s because until Vote Leave drop these two lies it is very difficult to have a serious debate with them about the EU budget, even though I actually agree with them that it is needed.