The number one priority for the U.K. government regarding the Brexit negotiations is to come up with a plan that benefits everyone, Mayor of London Sadiq Khan has told CNBC.
"The problem with a 'hard Brexit' is there aren't any winners. A 'hard Brexit' is no good for London and the U.K., and is no good for the EU," Khan told CNBC's Tania Bryer.
"What's really important is access to a single market. What's really important is the ability to carry on attracting talent. What's really important is a relation to financial jobs with passport financial services."
A so-called "hard Brexit" would be where the U.K. loses access to the EU's single market and defaults back to World Trade Organization rules. In a "soft Brexit" scenario, the U.K. would retain some form of membership to the single market.
Speaking at the annual switching on of Oxford Street's Christmas lights, Khan — who is a member of the U.K.'s opposition Labour party —said during these negotiations it was important for the U.K. capital to also have "a seat around the table."
The mayor added that he hoped that the government would listen to the public's needs, as while Britons may have voted to leave, they hadn't voted to come out with a deal that provided "fewer jobs, less prosperity and less growth."
His comments come after the U.K.'s High Court ruled last week that any proposed Brexit plan would have to be approved by all lawmakers in parliament before triggering "Article 50". This instigated anger from some politicians and some U.K. newspapers.
On Sunday however, U.K. Prime Minister Theresa May said she respected the independence of the judiciary, adding that the government believed it had strong legal arguments when it comes to appealing the ruling, according to Reuters.
In reaction to the latest developments surrounding Brexit, London's mayor said the key issue for government now is to show it's got a game plan prior to triggering the formal process of leaving the EU, which is expected to take place next year.
"They need a plan before 'Article 50' is served. They've got to plan to make sure what we negotiate with the EU, the deal we get is good for London, is good for our country, good for the EU, and good for businesses. It's really important," he said.
While there is fear that foreign investors could be put off by London and the U.K., Khan argued otherwise saying at present, investors have heard London's message that it is open as a city — open to people, talent and ideas.
The mayor added that the city had to provide reassurance to these investors, and show those from outside the U.K. that London has some of the "most talented people in the world" and that the city still wants to — and will always want to — do business with foreign investors.
"They love London. They love the U.K., they want to carry on doing business with us, and the government's job is to make sure they get a good deal with the EU."