A City lawyer has warned commercial disputes could move abroad unless the government secures favourable Brexit negotiations.

Ed Crosse, a partner at Simmons & Simmons and president of the London Solicitors Litigation Association, said clients will stay loyal to English courts in the near future, but they will consider issuing elsewhere if the terms are no longer favourable.

Crosse cited the potential departure from the Brussels Regulation – which sets out regulations for litigating and jurisdictional issues – as something that must be a key element of exit negotiations.

Other systems, such as the European Economic Area model, which provides a template for a country outside of full membership of the European Union, would be attractive but would need agreement from all 27 states, said Crosse.

The financial disputes expert stressed English law remains the first choice for international litigants, but with 60% of cases in the High Court involving at least one party from overseas, the status quo could change.

‘English law is in most commercial agreements and that is our commodity in keeping disputes in the English courts,’ he told the Bond Solon witness conference in London. ‘It is too big a leap to go to France.

‘But there is a question [over England and Wales] and on the continent this is seen as an opportunity for them. If we don’t get these agreements with the EU we will see an added layer of complexity.

‘Clients that were concerned about instructing overseas may feel English litigation is too slow and expensive. [The Brussels Regime] are regulations that really benefit us and without them we have a real problem.’

Crosse said the biggest migration may be to settling cases on the continent through arbitration.

And he warned that even without the issue of Brexit, clients are beginning to question whether litigating in England is getting too expensive.

‘Increasing feedback from the FTSE 100 is that London is becoming too expensive – the area that is most criticised is disclosure and particularly electronic disclosure.'