Some Tory MPs have told the BBC such a ballot could be triggered this week, as the prime minister continues to face calls to resign over lockdown parties.

On Sunday ministers publicly backed the PM to win a vote, should one be called.

Business minister Paul Scully told Channel 4 that a vote "may well" happen - but Mr Johnson "will face it down".

Transport Secretary Grant Shapps also told the BBC the prime minister would not lose a confidence vote among his own MPs.

In the 10 days since MPs returned to their constituencies for the half term break, speculation has swirled about whether Mr Johnson will face an internal electoral battle to save his premiership.

For a confidence ballot to be triggered, 54 Tory MPs must formally put in a letter to Sir Graham Brady, the chairman of the 1922 Committee of backbench MPs, asking for one.