As the desperate wait goes on for any sign of white smoke above Brussels, a new report lifts the lid on exactly how ill-prepared businesses are for Brexit.

As negotiators frantically try to thrash out the terms of a deal ahead of a 48-hour EU summit and an extraordinary sitting of parliament on Saturday, the prospect of the cliff edge is edging ever closer.

And against that dire backdrop, today’s report by the National Audit Office makes for yet more grim reading.

It finds that despite the £140m thrown at the Get Ready for Brexit campaign, one of the biggest information campaigns in government history, legions of companies are still not prepared for a no-deal.

Trade with Europe, it predicts, would be thrown into chaos on day one of Brexit, which could be as early as 31 October, if the Benn Act fails to force the PM to ask for another Brexit extension at the weekend.

According to the NAO, government attempts to ramp up no-deal planning has had a “limited impact”. Up to 225,000 businesses are still not registered to make customs declarations in the event of a no-deal, while as few as 5% of SMEs are prepared for the new procedures at Calais.

What should retailers be doing to prepare for a no-deal Brexit?

That’s without mentioning the potential chaos in Northern Ireland which, of course, has been so central to the ongoing talks.

The report confirms the doom-laden projections of Operation Yellowhammer, which ministers have desperately tried to play down based on the central argument that no-deal preparations have taken off under Boris Johnson’s government.

So will ministers try to accuse their own parliamentary scrutiny body of scaremongering, or somehow being part of ‘Project Fear’? They did try to do this with the Yellowhammer leaks, despite it being the government’s own “reasonable” worst-case scenario.

One of the big fears as far as business leaders are concerned is that the finger of blame could yet be pointed at them, rather than government.

Sources have for several weeks now been voicing their concerns that, with tens of thousands, if not hundreds of thousands, having failed to prepare for Brexit, they will end up carrying the can.

So it will be retailers’ fault if there are empty shelves, the fault of logistics companies if Dover turns into a giant lorry park, the problem of suppliers if tariffs lead to soaring prices?

If MPs think they can get away with such smoke and mirrors, surely they are in for a rude awakening.

Trade bodies have been warning for three years of exactly the sort of chaos at the border predicted by the NAO. They have also been calling for a large part of that time for greater clarity form the government on the key issues facing businesses, many of which remain unanswered.

As The Grocer’s own Brexit preparedness online resource shows only too clearly, the list of issues facing companies is huge, with vital advice on areas such as import tariffs emerging far too late to enable companies to get ready.

Many companies have simply found the challenge overwhelming, while others, having seen previous deadlines for Brexit come and go despite spending tens of millions stockpiling, have refused to do it all again. And who would be surprised if they were vindicated again come the weekend?

The £140m readiness campaign was launched in September, less than two months before the deadline for a no-deal. What sort of planning is that?

Yes, there will be businesses who have failed to do all they could to prepare, but it’s not in the most part these people who have been beating their chests at the prospect of Britain leaving the EU and urging the PM to get the job done.

Responsibility must lie with those politicians gathering in Brussels this week and at Westminster on Saturday. They must do all they can to try to avert this all-too-predictable catastrophe.