A court ruling on Thursday has created upheaval throughout the U.K., based on its decision that any Brexit plan would have to be approved by all U.K. lawmakers.  This has radically changed the outlook for the country's divorce with Europe, leading one senior economist to say: "(It) has the potential to materially change the calculus of Brexit."

The court ruled that the entire U.K. parliament must vote on whether the country can start the process of leaving the European Union. This deals a blow to Prime Minister Theresa May, who had argued that the government on its own could trigger "Article 50" and start the divorce with the European Union, despite criticism that this was unconstitutional.

There had been concerns that lawmakers at the heart of the U.K. government would opt and force through a so-called "hard Brexit" without the consent of parliament. Politicians in the U.K. mostly campaigned to stay in the EU despite the wider public voting for the opposite. With the court ruling, it now makes it less likely that a "hard Brexit" scenario - which could have meant a loss of access to the EU's single market - could be carried through.

This also has implications for banks, with the City of London voicing concerns that it might lose its "passporting" rights. These rights allowed American banks to set up their European sales operations in London which was seen gateway to the European market.