The UK's European Commissioner Lord Hill is to stand down, citing his "disappointment" in the UK decision to leave the European Union - something that "cannot be undone".
In a statement issued Saturday, Hill said he did not believe it was right for him to carry on with his work as the commissioner in charge of financial services, but said he would stay on for a period of weeks to ensure a smooth handover.
European Commissioners are among the most powerful officials in Brussels, with the ability to make laws across a range of policy areas. The UK will cease to have one when it leaves the EU which founding members on Saturday urged the UK to do as a matter of urgency, saying it could not "play cat and mouth" with its soon-to-be former partners.
Hill, whose resignation follows that of Prime Minister David Cameron, said: "Like many people here and in the UK, I am obviously very disappointed about the result of the referendum.
"I wanted it to end differently and had hoped that Britain would want to play a role in arguing for an outward-looking, flexible, competitive, free trade Europe. But the British people took a different decision, and that is the way that democracy works."
Hill, 55, said he did not "believe is is right that I should carry on" as the British Commissioner as though "nothing had happened".
He said he was "very grateful" to the president of the European Commission, Jean-Claude Junker, for giving him the chance to work on financial services and for the "opportunity to help support jobs and growth in Europe".
Hill said he had come to Brussels as someone who had campaigned against Britain joining the euro, and "sceptical about Europe".
However, he added: "I will leave it certain that, despite its frustrations, our membership was good for our place in the world and good for our economy.
"But what is done cannot be undone and now we have to get on with making our new relationship with Europe work as well as possible."
Hill's announcement came as Scotland's First Minister Nicola Sturgeon said she would be seeking "immediate discussions" with Brussels to "protect Scotland's place in the EU". Given Scotland voted in favour of Remain.
Sturgeon said a new Scottish independence referendum was "highly likely".