A few years ago the American comedian Stephen Colbert, imitating a Right-wing shock jock, coined the phrase ‘truthiness’ to describe the art of asserting one’s beliefs as if they are facts. “Anybody who knows me knows that I’m no fan of dictionaries or reference books. They’re elitist.” he declared. “Who’s Britannica to tell me the Panama Canal was finished in 1914? If I wanna say it happened in 1941, that’s my right.

I don’t trust books. They’re all fact, no heart.”

Nigel Farage, Nigel Lawson, Michael Howard, Boris Johnson and the rest of the Brexit crew are increasingly treating the EU like Colbert treated the Panama Canal: they’re just making things up. If their heart tells them they don’t like a fact, they merrily make up another one. Every time anyone reasonably points out the risks of yanking ourselves out of the world’s largest marketplace they yell that it’s “Project Fear”. Yet they have come up with their very own Project: Project Fib.

Here, then, are the five fattest fibs from Project Fib:

The first is the claim that our membership of the EU costs us £55 million a day, a figure repeatedly used by Farage, Johnson and others. It’s a total con. As the fact-checkers at InFacts have found, in 2015 the net cost was in fact £17 million a day, or around 30p per person. For that entry fee we then get all the benefits that our access to the world’s largest single market brings, which the CBI has estimated to be worth £3,000 to every British household. So every man, woman and child materially benefits many times more than what we pay in.

The second is that, when it comes to trade, the EU needs us more than we need it. At a debate I took part in last week, this was the very first point made by Tory minister Andrea Leadsom. Again, totally bogus. Our exports to the rest of the EU represent around 12 per cent of our GDP but the EU’s exports to us are just three per cent of its GDP. Neither side will want a trade war but we should be under no illusion that the EU would have the much stronger hand to play in any negotiations if we left.

The Ukip claim after Brussels this week that our EU membership is synonymous with terrorist atrocities marked a new low in Project Fib Nick Clegg

The third is that fewer than 750,000 Brits live elsewhere in Europe, far fewer than the number of EU nationals who live in the UK, a fib that Farage used against me in that same debate. But his figure is complete baloney. The Government’s own estimates a few years ago suggested around 2.2 million British people were living at least part of the year elsewhere, which is only slightly less than the 2.3 million EU citizens estimated to be living in the UK. The right to live and work across the EU is a two-way street.

The fourth is that EU “red tape” costs British businesses £600 million a year, a figure cited recently by Boris Johnson, and that the UK is run by a monstrously bloated bureaucracy in Brussels. For a start, this fib is based on the cost of applying regulations not just to business but to the public sector too. And, as with the £55 million-a-day figure, it takes no account of the return we get, either in terms of matters such as cleaner air or the huge benefits those same businesses get from being able to trade freely in the world’s biggest marketplace. And the European Commission is in truth about a 10th the size of Whitehall, employing around half the number of officials employed by HMRC alone.

But the fifth is perhaps the most pernicious. It is the claim that if we withdraw from Europe we can somehow “reclaim our borders” and wish the problem of mass immigration away. The Farages of this world like to suggest that if we were not part of the EU fewer desperate refugees fleeing war in Syria and elsewhere would seek to make their way here. What cynical nonsense. The truth is that we are not part of the borderless Schengen area and the thousands of traumatised individuals clamouring for refuge in Europe do not make a distinction between EU and non-EU membership. They just want safety and sanctuary. What’s more, if we want to trade with Europe in future as we do now, free movement will undoubtedly be part of the deal. That’s what Norway and Switzerland, which the Brexiteers love to cite as models, have found. Both have to sign up to the EU’s rules in order to be part of the single market (even partially in Switzerland’s case), and we would too.

If you believed everything the Eurosceptics said, you would think Britain was some impotent basket case, its leaders toothless, its businesses drowning in bureaucracy, and its fate in the hands of stern-faced Germans and perfidious Frenchmen all hellbent on helping hordes of dodgy foreigners clamber up the white cliffs of Dover.

But it isn’t. We are not a bulldog in a muzzle, unable to bark. We are the world’s fifth-largest economy. We sit at the top table of world affairs, from the G8 to Nato and the UN Security Council. We are among the world leaders in everything from green technologies and gaming to television dramas and top-flight football. All these things are enabled by our membership of the EU, not diminished by it.

The EU is not perfect. Of course not. We have a free choice to decide the fate of our country on June 23. But the least the Leave camp could do is stop fibbing its way to the finishing line. The claim from Ukip within hours of this week’s tragic events in Brussels that our EU membership is synonymous with terrorist atrocities marked a new low in Project Fib.

It is not Project Fear that you should worry about, it is Project Fib. The decision we will all make in a few weeks’ time is one that will affect the course of our country for decades. It should be made on the basis of facts, not truthiness.