It's uncertain what happens after a no confidence vote

A very timely review of the Fixed Term Parliaments Act and the issue of confidence motions: Public Administration Committee

Should a vote of no confidence in the Government be passed, it is unclear what would happen next: 'The Act provides no guidance on what occurs during the 14-day period following an Fixed-term Parliaments Act 2011 no confidence motion being passed. As the Clerk of the House told us, what occurs during this period is a matter politics, and not of procedure. Evidence to this inquiry and the Cabinet Manual set out that the Prime Minister would be expected to continue in office unless someone else could command the confidence of the House.'

'If someone else could command the confidence of the House, the Prime Minster would be expected to resign. Not doing so would risk drawing the Sovereign into the political process, something the Cabinet Manual is very clear it intends to avoid. At any point during this period, a motion of confidence in Her Majesty’s Government under the Fixed-term Parliaments Act 2011 could be put down and that that would prevent the election. After 14 days a general election would automatically follow.'