Ministers still do not “grasp” the complexities of leaving the European Union, the British judge on the European Court of Justice has privately warned, questioning the calibre of politicians negotiating Brexit.

Ian Forrester, Britain’s representative on the European Court of Justice for the past two years, candidly told Irish diplomats that there were “issues around the quality of politicians in Westminster at present”.

He expressed his hopes that it would “gradually dawn on people” what leaving actually entailed and for a “realisation” that it was a “great mistake”.

The comments were contained in a confidential Irish government report leaked to RTÉ News. The paper also included withering assessments of British politicians and officials from senior figures from across the European Union.

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