When Theresa May rolled the dice on April 18 and called a snap election, she said it was the only way to "guarantee certainty and stability for the years ahead".

Instead, her out-of-character gamble has delivered precisely the opposite result. Rather than securing an unequivocal mandate for her Brexit plan and neutralising a fresh push by Scottish nationalists, May has plunged Westminster into a period of chronic instability at a time when the UK faces the most critical constitutional challenge in its postwar history.