The bloc offered Britain a Brexit deadline at the end of October to avert a no-deal withdrawal that was set to take place on Friday evening.
A growing number of countries are now eager to punish Facebook and other internet companies for harmful material on their platforms.
A no-deal Brexit, once unthinkable, could happen in less than two weeks, barring a deadline extension. Here are some of the likely consequences.
Could Brexit reignite the Troubles in Northern Ireland?