Sir Ivan Rogers, Britain's EU ambassador, declared to quit his job.
Independent: Sir Ivan Rogers quits: Britain's EU ambassador attacks 'muddled' Brexit thinking in scathing resignation letter
It was scheduled for him to remain the seat of ambassador till this November. But he left the post all at sudden. His resignation letter suggests that he was suffering from continuous ignorance to his warning by the domestic authorities.
International Business Times: 'Never be afraid to speak the truth to those in power,' UK's departing EU diplomat tells colleagues
Rogers seemed to have had an opinion that the UK should not leave the EU. It is acceptable that he was mourning at the post to prepare for Brexit against his own ideology.
Some people claim that Rogers' resignation is not a tragedy but a chance to appoint a preferable person as his successor. Indeed, someone with an opinion of Eurosceptics would be motivated to be involved in the negotiation.
However, it must be a headache for Theresa May, the Prime Minister of the UK, to lose the ambassador who is skilled and familiar with the newest situation. Also, the UK seems to have few people with good leadership to integrate citizens' mind to Brexit, considering the current behaviors of Nigel Farage.
At last, Sir Tim Barrow officially succeeded Rogers' post.
Telegraph: Sir Tim Barrow will succeed Sir Ivan Rogers as Britain's ambassador to the EU
I think that the way to Brexit became more painful because of this incident.