So what if we walk?

FLAGGING Union Jack and EU banners outside Commission HQ in Brussels HERE’S the negative side of what could happen if talks fail:

TRADE PARALYSED We would be out of the single market and customs union. Free trade with the EU, our largest trading partner, and dozens of other countries would halt and we would have to fall back on World Trade Organisation rules.

This would mean 10% tariffs on car exports, 22% on lorries and up to 40% on some farm goods.

A report by MPs warned trade with the EU would fall by up to 29%, costing us between £48.6billion and £58billion – the equivalent to between £741 and £884 per person. The Treasury is equally pessimistic, saying it could cost 800,000 jobs, cut GDP by 6% and see the pound fall by 15%.

BUSINESS COSTS RISE Nissan boss Colin Lawther told MPs that falling back on WTO rules would cost the firm £500million a year in import and export duties.

Financial services would lose the rights to sell products across the EU and need individual licences for each country. Tens of thousands of jobs could go in banking, insurance and trading. The Financial Conduct Authority says 5,476 British firms rely on passporting rights.

FOOD PRICES RISE Sainsbury’s has warned of dearer prices, delays and the risk of empty shelves because of extra customs checks, and increased waste.

The Resolution Foundation says tariffs on imports of dairy products from the EU would rise by 45%. Meat products would go up 37% and clothing, footwear, beverages and tobacco 10%. Three million of our poorest households would face price rises of over £500 a year.

MILLIONS LEFT IN LIMBO The status of 3.2 million EU nationals in the UK and the one million UK nationals in the EU would be thrown into uncertainty.

Brits could lose free emergency healthcare. The NHS says tens of thousands of OAPs would be forced to return home, putting an added £500million a year strain on the service. Travellers would face extra queues and we could need visas for the EU. Brits may face immediate European phone-roaming charges.

QUEUES AT CUSTOMS All lorries to and from our ports would be subject to customs checks. Experts say at least eight square miles of land needs to be set aside at each major port to cater for hauliers awaiting clearance.

SECURITY AT RISK We could lose access to the European Arrest Warrant which allows the extradition of terrorists, murderers, rapists and paedophiles, and sharing of intelligence.

The UK would also lose access to databases which store DNA, fingerprint and vehicle information.

NORTHERN IRELAND PEACE PROCESS IN JEOPARDY Crashing out could require a hard border with the Republic which could inflame Republican tensions. Life would be severely disrupted. Around 30,000 people cross the border each day.

FLIGHTS COULD BE GROUNDED Airlines and aerospace firms are overseen by the European Aviation Safety Agency. The Airport Operators’ Association says they have no equivalent to falling back on WTO rules. It warns that unless the legal vacuum is addressed flights could be stopped.

Ryanair has also warned flights could be grounded. Thomas Cook has already changed its terms and conditions so it will not be liable for delays caused by “airspace closures” after March 2019.

ACCESS TO MEDICINES Leaving EU nuclear agency Euratom threatens the supply of isotopes used in scans and radiation treatment.

Pharma companies warn border delays could pose a “serious threat” to supplies of medicines.

Drug firms could have to leave the UK in order to keep their EU-licences for products.

ARE THERE ANY POSITIVES? Brexiteers claim we would save the £12billion a year we pay the EU. But if we fail to settle our divorce bill it will make it harder to strike a future deal with Brussels.

They also claim we would no longer be subject to EU red tape and free from EU tariffs applied to the rest of the world which would boost our economy by £120billion.

But this would only be the case if we strike trade deals with non-EU countries that compensate for the loss of access to the single market.

It would also require the UK to become a low-tax, low-regulation country threatening investment in public services and the scrapping of workers’ rights.