Boris Johnson is having a worse day than the sterling bulls.
Bhatti tweeted out his own resignation letter, saying "The Conservative party has always been the party of integrity and honour but recent events have undermined trust and standards in public life. It is for this reason that sadly, I must resign."
Update: Jonathan Gullis, MP for Stoke on Trent, has also resigned from his positions as a parliamentary press secretary to the secretary of state for Northern Ireland.
Update 2: And Jo Gideon.