John Bercow has acknowledged using the word “stupid” in a Commons spat with the Government, amid claims it was aimed at a senior female minister.

The Speaker said his use of the adjective “simply summed up how I felt” about how business in the Commons had been conducted after time for debate on Grenfell Tower was shortened by a ministerial statement on the East Coast Main Line.

Mr Bercow added he respects all of his colleagues and said MPs would not have the “slightest doubt” about Commons Leader Andrea Leadsom’s political ability and personal character.

He was alleged to have branded Mrs Leadsom a “stupid woman” and “f****** useless” in an aside in the chamber on May 16.

But Mr Bercow offered no apology and remained defiant about his approach as he insisted he will “continue to speak out firmly” for the interests of the Commons and publicly disagree with the Government’s management of business.

Speaking in the debate after Mr Bercow’s latest statement, Mrs Leadsom outlined how she took her responsibilities “very seriously” and she expected all MPs to treat colleagues with “courtesy and respect”.

The row came amid mounting pressure and scrutiny on Mr Bercow, who has faced calls to resign over allegations of bullying staff who worked for him. He has denied the claims.

Mr Bercow told MPs: “Last Wednesday, the Government chose to schedule a major transport statement on an opposition day – thereby substantially reducing the time available for Opposition business.

“I thought then, as I think now, that this was very badly handled. It was in particular disrespectful both to the House and to the 23 backbenchers who were hoping to participate in the Opposition Day Debate on the Grenfell Tower disaster.

“It was in that context and that context alone that having expressed my displeasure about the matter quite forcefully from the chair I used the word ‘stupid’ in a muttered aside.

“That adjective simply summed up how I felt about the way that day’s business had been conducted.

“Anyone who knows (Mrs Leadsom) at all well will have not the slightest doubt about her political ability and her personal character.

“I love this House, I respect all of my colleagues, I hold you all in the highest esteem.

“It is our duty to get on with the business of Parliament, scrutinising legislation, debating issues and standing up for the people we are here to represent.

“For my part I will continue to speak out firmly for the interests of the whole House and if from time to time it involves publicly disagreeing with the Government’s management of business, then so be it.”

Mrs Leadsom, speaking at the despatch box in an emergency debate on money resolutions for private members’ bills, said: “I take my responsibilities to this House very seriously. As you said last week Mr Speaker, we have a responsibility to safeguard the rights of this House.

“As Leader of the House, I seek to do exactly that, treating all Members of Parliament with courtesy and respect.

“I hope and expect all honourable and right honourable members to do likewise.”