Explainer: What happens next after UK PM Johnson writes Brexit delay letter?

Britain's Prime Minister Boris Johnson speaks ahead of a vote on his renegotiated Brexit deal, on what has been dubbed "Super Saturday", in the House of Commons in London, Britain October 19, 2019. ©UK Parliament/Jessica Taylor/Handout via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY

LONDON (Reuters) - Prime Minister Boris Johnson has sent an unsigned letter to the European Union requesting a delay to Britain's exit from the bloc, as well as a second note saying he did not want a "deeply corrosive" Brexit extension.

Johnson was required by law to send the first letter, after parliament voted on Saturday to withhold its approval of his Brexit deal until it has passed legislation to formally ratify the agreement.