Allegra Stratton has resigned as an adviser to Boris Johnson after footage emerged of her joking with senior aides about Downing Street’s Christmas party.
In a statement she said: ‘My remarks seemed to make light of the rules, rules that people were doing everything to obey.
‘That was never my intention. I will regret those remarks for the rest of my days and offer my profound apologies to all of you.
She added: ‘I understand the anger and frustration that people feel.