Barack Obama has warned that Britain would go to "the back of the queue" for a trade deal if voters opted to leave the European Union in the upcoming referendum.

He was talking about the trade negotiations between the EU and the US, known as TTIP (the Transatlantic Trade and Investment Partnership), which he says Britain could miss out on if it leaves the EU.

 Transatlantic negotiations
Image: Brookings

While Obama is keen to advance the TTIP, he is facing a growing tide of concern about the impact on jobs, consumer protections and the environment. Before Obama’s visit to Germany, thousands of protesters turned out to express their opposition to the deal.

So what is the TTIP and why does it matter?

It’s a deal currently being negotiated by the US and EU that would cut tariffs and regulatory barriers to transatlantic trade and foreign investment. It aims to make it easier for companies on both sides of the Atlantic to access one another’s markets.

The US and EU countries together represent $1 trillion in trade every year. If a deal is reached, it would cover 45% of global GDP, making the TTIP the world’s largest trade agreement. The agreement would affect industries including pharmaceuticals, automotive, energy, finance, chemicals, clothing and food and drink.

Why is it so controversial?

Supporters claim the pact could boost economies on each side of the Atlantic, as well as creating jobs, increasing wages, lowering prices and improving consumer choice.

A study by the Centre for Economic Policy Research (CEPR) estimated the potential gains for the EU to be up to €119 billion ($134 billion) a year and €95 billion ($107 billion) for the US. The research, carried out for the European Commission, found wages would be higher by 0.5% in the EU and just under 0.4% in the US.

Opponents dispute these figures, arguing that the treaty would leave people worse off because it would favour the interests of big corporations, destroy jobs and remove regulations designed to protect health and the environment.

A study by Jeronim Capaldo of the Global Development and Environment Institute at Tufts University argues that the TTIP would result in the loss of 600,000 European jobs, a net decline in EU exports, falling GDPs for EU member states and a reduction in Europeans’ personal income.

Why would a post-Brexit Britain go to the back of the queue?

Obama has said it would be easier for the US to negotiate with the EU as a bloc, rather than make "piecemeal trade agreements" with individual countries. During his three-day trip to the UK, the US president said the UK “would not be able to negotiate something faster than the EU”, and it could take up to 10 years to secure any post-Brexit trade deals.

Although the US does not appear to be willing to fast-track a separate free-trade deal with the UK, the out campaign would argue this stance could change after a Brexit vote.

 What is the transatlantic view of Brexit?
Image: BritishAmerican Business (BAB)

When would the deal be agreed?

Obama has said he hopes the deal could be agreed this year but acknowledges that final ratification by US Congress will take more time – the first deal in the queue is the Trans-Pacific Partnership.

Speaking during his trip to Germany, he said: "If we don't complete negotiations this year, then upcoming political transitions in the United States and Europe would mean this agreement won't be finished for quite some time."