Just days after voting to leave the European Union, more than 2-and-a-half million UK residents have signed a petition calling for a second referendum. The British Parliament has to consider a debate on any petition with over 100,000 signatures posted on its website.

The proposal was posted before Thursday's referendum. It suggests the government should hold another vote on EU membership if the support for either "Leave" or "Remain" was less than 60 percent ... in a turnout of under 75 percent of eligible voters. Thursday's results showed 52 percent of voters backed leaving the EU, on a turnout of 72 percent.