Explainer: What does David Frost’s resignation mean for Boris Johnson’s future as British PM?

Prime Minister Boris Johnson (Tolga Akmen/PA)
The departure of David Frost from Boris Johnson’s Cabinet has been described as a “watershed moment” for the PM as his backbenchers spoke openly about needing a new direction for his party and Government.
Mr Frost’s resignation could hardly have come at a worse time for Mr Johnson, who has faced potentially the most damaging week in his premiership.