One of the German regulators with the power to veto the proposed tie-up between Deutsche Börse and London Stock Exchange Group has said Britain's decision to leave the EU throws up fresh questions about the future of the deal.

Hesse is one of the German federal regulators that must give the merger permission to proceed and Tarek Al-Wazir, the Hessian economic minister of the Green Party, said in videos posted on his Facebook page on June 24: "Brexit is a bad decision, a bad decision for Europe, for Germany and Hesse, but also for the UK."