With the British having voted to leave the EU, it's now come down to whether it will be a "hard" or "soft" Brexit.
And as Prime Minister Theresa May has learnt, financial markets are taking a keen interest in any hint she gives about her government's intentions.
The pound sterling fell to a ten-week low after she appeared to indicate Britain was heading down the "hard" Brexit road: prepared to sacrifice EU market access for tougher border controls.
Asked at a public meeting if her comments had been interpreted wrongly, Theresa May tried to clarify just what message she was sending.
"I don't accept the terms hard and soft Brexit. What we're doing is going to get an ambitious, good and best-possible deal for the United Kingdom in terms, as I say, of trading with and operating within the single European market but it will be a new relationship because we won't be members of the EU any longer, we will be outside the European Union and therefore we will be negotiating a new relationship, across not just trading but other areas, with the European Union."
The PM denied Britain was trying to "pick and choose" the most favourable aspects of its European alliance.
"We mustn't think of this as sort of leaving the EU and trying to keep bits of membership, what bits of the membership will we keep? It's a new relationship, we'll be outside the EU, we will have a new relationship but I believe that can be a relationship which has a good trading deal at its heart. As I say, the best possible deal for the UK but also I think that that deal for the UK would also be good for the rest of Europe as well."
And in the lead-up to Brexit negotiations, it's not just financial markets watching closely what Theresa May has to say.
EU leaders are keen to reinforce they won't be pushovers when it comes to saying farewell to Britain.
German Chancellor Angela Merkel says Union free-access rules must be followed if trading bloc relations remain.
"Germany and Great Britain are friends. At the same time, we must also make clear on the other hand that access to the single market can only be possible on the condition of respecting the four basic freedoms. Otherwise one has to talk about limits of access. These negotiations can not be based on cherry-picking because that would have disastrous consequences on the other 27 member countries."
It's a sensitive time for Britain politically and economically - sensitivity only heightened by a series of rail network strikes.
A 24-hour walkout by London underground station staff has caused travel chaos, with estimates it could cost the economy tens of millions of pounds.
The Chief Executive of the London Chamber of Commerce and Industry, Colin Stanbridge, fears the strike could also tarnish London's image as one of the world's major economic and financial powerhouses.
"What's more important, in some ways, is the message that it sends around the world. You know we are trying to deal with Brexit, London voted overwhelmingly to stay in the EU, we're coming to terms with making a success of being out of the EU. But we can't, we don't, we can't have this message going around the world at this time that London somehow is closed or that it's difficult to do business in London, or it's difficult as a tourist."
For one iconic British manufacturer, business has been good amid the Brexit uncertainty ....
In 2016, luxury car producer Rolls Royce drove the second-largest number of sales in its 113-year history.
The BMW-owned company's chief executive, Torsten Muller-Otvos, has committed to retaining manufacturing operations in the UK but has a message for Brexit negotiators.
"That uncertainty which is currently in the market around what will happen and so on, is not really good, because it is affecting consumer sentiment in a negative way. I am of course highly interested in excellent trade relations with all our markets worldwide, and for that reason I would very much appreciate if the UK would stay in the European market."
