Education minister Andrea Jenkyns has admitted she “should have shown more composure” after making a rude gesture to a “baying mob” outside Downing Street.
Ms Jenkyns, who made the sign with her hand as she walked through the black gates, prior to her new appointment, said in a statement: “I had reached the end of my tether”.
She said she stood up for herself after being subject to “huge amounts of abuse” over the years, including two death threats in recent weeks.
“I should have shown more composure but am only human,” she added.
Commons Leader Mark Spencer had said it was up to Ms Jenkyns to “justify” her actions after she was caught on camera making the gesture.
He told BBC Breakfast: “I don’t seek to condone that at all.
“I mean, Andrea will have to… justify that for herself.
“But I do understand emotions were running pretty high and they were pretty raw on that day.
“But I don’t think that was the right thing to do at all.”
Pressed on whether she should retain her ministerial role, he said: “That’s not my decision.”
Ms Jenkyns was appointed to the role of parliamentary under-secretary of state at the Department for Education on Friday in a reshuffle by Prime Minister Boris Johnson.
The footage, shared on social media on Thursday evening, appears to have been filmed shortly before Mr Johnson announced he was stepping down as leader of the Conservative Party.
In response to the video, shadow education secretary Bridget Phillipson tweeted: “Ministers aren’t expected to be perfect.
“But is it really too much to ask that they don’t treat the public like this?”
In her statement shared on Twitter, Ms Jenkyns said: “On Thursday afternoon I went to Downing Street to watch the Prime Minister’s resignation speech.
“A baying mob outside the gates were insulting MPs on their way in, as is sadly all too common.
“After receiving huge amounts of abuse from some of the people who were there over the years, and I have also had seven death threats in the last four years.
“Two of which have been in recent weeks and are currently being investigated by the police, I had reached the end of my tether.
“I responded and stood up for myself.
“Just why should anyone have to put up with this sort of treatment.
“I should have shown more composure but am only human.”
But Geoff Barton, General Secretary of the Association of School and College Leaders, appeared to be less than satisfied with Ms Jenkyns’ statement.
Without directly referencing her explanation, or the incident in question, he tweeted: “In my 32 years as a teacher, 15 of them as headteacher, I inevitably dealt with moments of poor behaviour and inappropriate conduct – from young people and staff.
“I have to say, ‘I’m only human’ was never good enough as an excuse from any of them for any of it.”
The UK Russian embassy tweeted the picture, commenting: “British culture definitely has a new prospects with A.Jenkyns.”
The Department for Education has been contacted for comment.
The education minister was one of the MPs to show support for Mr Johnson outside No 10 on Thursday as he announced his resignation.
A timetable for the Conservative Party leadership contest is expected to be drawn up next week after the election to the executive of the backbench 1922 Committee.