Reuters reports

  • Threshold of 15% has been exceeded
  • Ballot to be held at 1800 to 2000 GMT today
  • Announcements will be made as soon as possible this evening

The pitchforks are out. Usually when something like this is made official, the people behind the challenge are quite confident that they'd be able to oust the current leader. It looks like today could be the last we'll see of Theresa May as prime minister. The pound dips on the headline here with cable falling to a low of 1.2478 from 1.2510 earlier.