The warnings follow Prime Minister Andy Burnham's announcement of a major review of European policy and a plan for a UK-EU summit later this year. Burnham, who stated that Brexit has "done more harm than good," is exploring options for a long-term relationship that range from a customs union to full re-entry. French President Emmanuel Macron and Spanish Prime Minister Pedro Sanchez welcomed the prospect, though Brussels officials remain wary of British policy volatility. UK carbon prices surged following the announcement.
