Theresa May will make an emergency trip to Brussels today to meet the senior figures negotiating Brexit.

She will accompany Brexit Secretary David Davis on the trip, which is anticipated to include dinner with the EU's Chief Negotiator, Michel Barnier, and the European Commission's President, Jean-Claude Juncker.

The Prime Minister and German Chancellor have both agreed that the Brexit negotiations must be a success for the good of both Britain and the European Union.

Mrs May made a phone call to Mrs Merkel yesterday urging her to retain her support for the Iran nuclear deal, which President Trump has proposed to destroy.

Both leaders agreed the need for "continued, constructive progress" instead of allowing Brexit talks to be distracted by the size of Britain's divorce bill.

A Downing Street spokesman confirmed Berlin and London remain committed to the Iran nuclear deal and to cooperate on Iran's destabilising regional activity. They also expressed their concerns over Tehran's ballistic missile programme.

Brexit negotiations have recently stalled after Mr. Barnier refused to continue discussions until a financial settlement was paid. Numerous member states and politicians have vowed to punish the UK for voting to leave the trading bloc, which would create a substantial black hole in Brussels' budget.

German car companies, including Volkswagen, which produce billions from British sales, will lobby the Chancellor to speed up trade talks during the Brexit negotiations.

The deadlock over the settlement bill is causing delays in talks about a trade deal.

The UK must honour its financial contributions

Brussels argues the UK must honour its financial contributions and pay enough money into the EU's budget until 2020. Yet German car manufacturers have expressed their concerns that the negotiations have not yet progressed to trade.

Ruth Lea, an economic adviser for Arbuthnot Banking Group, said Germany would have a lot to lose if the Brexit negotiations collapse. Her warning comes as British ministers have confirmed that the Government is preparing for the likely scenario of "no deal."

Ms Lea told that Germany has an enormous trade surplus with Britain and that they would suffer the most if no trade agreement is negotiated between both the UK and the EU.

She said the trading bloc's £90 billion surplus of visible trade is enormous, with Germany's surplus with Britain currently standing at £3 billion a month.

Jobs could easily be sacrificed if no deal is reached

The economist said jobs could be easily sacrificed if no deal is reached. Ms Lea said German politicians are more concerned with expanding the European federal state than the anxieties of German industrialists. She worries that behind closed doors, politicians secretly fear the prospect of no deal.

Ms Lea said the German Government must not be seen to be guarding the best interests of the European political project over its car manufacturers. She said the final outcome is dependent on the ability of car manufacturers to influence Berlin.

She concluded by saying German car manufacturers, French wine makers and Belgian chocolate makers fail to realise the size of their deficits with the UK, stressing EU countries act as significant markets to many other countries as well. The economist said the scale of potential tariffs could prohibit trade stability even further, advising Brussels not to protect the integrity of the European political project over damaging trade.

Britain is the second largest export market for German car manufacturers with a value of £26 billion.

Defending the EU's Single Market must be Brussels' main priority

Dieter Kempf, head of the BDI, which represents German businesses, said the British Government must limit the damage on both sides of the Channel.

He told The Observer that defending the EU's Single Market must be Brussels' main priority in order to maintain the integrity of its four freedoms: goods, services, capital and labour. He advised German businesses to draw up contingency plans for a "very hard Brexit."

The BDI's Managing Director, Joachim Lang, highlighted the importance of a transitional deal and stressed Britain's importance to Germany's economy.

Mr. Barnier and Mr. Davis concluded the fifth round of talks by confirming the likelihood of reaching no deal.