European Union threats that Britain would be forced to leave Europol after Brexit were today exposed as posturing, after the European Commission refused to rule out the UK having a continued relationship with the EU police agency, provided it paid for the privilege.

The admission that Britain could continue to work with Europol, which exchanges crime and counter-terrorism information and intelligence, undermines the hard-line stance struck by Michel Barnier, the EU’s chief Brexit negotiator, at the start of this week’s round of UK-EU talks.

On Monday, Mr Barnier warned that Britain would be forced to leave Europol and that the EU-UK split would weaken British security and counter-terrorism, in a rebuke to Theresa May, who was accused of using Britain’s world leading police and intelligence services as leverage in negotiations in March.

British sources said Mr Barnier’s comments, and later criticism of Britain for “ambiguity” over Brexit, were “ill-judged and unhelpful” in a war of words that has rumbled on all week.

On Wednesday, the EU’s Security Commissioner said that Britain could pay to be part of Europol, exposing Mr Barnier’s threat as posturing.

British conservatives welcomed the softer stance, pointing out that the UK makes a vital contribution to Europol, is led by a British civil servant, and that it is “strongly in the EU’s interest” that Britain remains a member.