Law firms are advising their clients to reaffirm England and Wales as their chosen jurisdiction for dispute resolution in case of a no-deal Brexit, according to several partners.

Failure to do so would risk E.U. member states not necessarily recognising English courts as the default jurisdiction to settle disputes, leading to fewer disputes being handled within the U.K. legal system.

"The concern is that some clients and some law firms may feel that they need to reconsider that the precedent of choosing English courts and English law is necessarily still the right thing for their clients," said Jonathan Harris QC at Serle Court Chambers. "They may very well conclude that they are, but even if they are thinking of that question, it goes to the fact that a small but significant minority of clients may ultimately think to move away from the English courts."

The stakes are very high, he said, adding: "It's difficult for English lawyers to think of anything more important than whether clients will choose to dispute under English law."

Simmons & Simmons financial markets managing associate Elizabeth Williams said clients are now going to have to consider other options. "We're really going back to a landscape that was last seen in the 1980s, which was a bit of patchwork quilt across Europe about enforcing judgments," she said.

But Harris said that if the U.K. leaves the E.U. with a withdrawal agreement, the issue will be less pressing, as the two-year transition period takes hold.

At Legal Week's Commercial Litigation and Arbitration Forum in November, the former head of the Commercial Court Mr Justice Popplewell warned that overseas courts could seek to challenge the U.K.'s status as a well-respected centre for dispute resolution.