Allegra Stratton has resigned from her government job after a video emerged of her joking about a No.10 party alleged to have been held at the time of strict lockdown restrictions.
Stratton had most recently served as spokesperson for the COP26 climate change summit.
Speaking to broadcasters on Wednesday afternoon outside her home, she said: ”I understand the anger and frustration that people feel.
“To all of you who lost loved ones, endured intolerable loneliness and struggled with your business - I am sorry and this afternoon I have offered my resignation to prime minister.”
She added: “My remarks seemed to make light of rules, rules that people were doing everything to obey. That was never my intention.”
On Tuesday evening ITV published a video which showed Stratton, in her previous role as Boris Johnson’s press secretary, appearing to make fun of the party.
During PMQs, the prime minister apologised “unreservedly” for the offence caused by the footage and said he was “furious”.
He has asked the cabinet secretary to investigate claims a party was held that was in breach of Covid rules.
But Keir Starmer, the Labour leader, said the public would think the prime minister was “taking them for fools”.