JOHN Bercow, the Commons Speaker, has been reported to Westminster’s standards watchdog over claims he branded Cabinet minister Andrea Leadsom a "stupid woman" and "f****** useless".

Tory backbencher James Duddridge said he had made a formal complaint to Kathryn Stone, the Parliamentary Commissioner for Standards, over the alleged May 16 outburst in the chamber directed at the Commons Leader.

On Monday, Mr Bercow admitted using the word "stupid" but offered no apology.

He said he would "continue to speak out firmly" for the interests of the Commons and publicly disagree with the UK Government's management of business, which is led by Mrs Leadsom as the Commons Leader.

In his letter to the Commissioner, Mr Duddridge said he believed Mr Bercow's actions breached the Commons' 2009 code of conduct, which states: "Members shall at all times conduct themselves in a manner which will tend to maintain and strengthen the public's trust and confidence in the integrity of Parliament and never undertake any action which would bring the House of Commons, or its Members generally, into disrepute."

The Rochford and Southend East MP wrote: "We cannot let the current situation of intimidation and bullying from such a senior figure whom we should look to set an example and act as arbitrator.

"The perpetrator cannot be allowed to have so much power over the House, its members and staff who work in the Commons. It is essential that the Speaker steps aside from chairing and participating on all matters related to bullying."

He also asked for a call to evidence over "intimidating behaviour which I and other members have witnessed repeatedly over the years".

The Commissioner's office confirmed it had received a complaint and she would "consider whether the matter is within her remit and, if it is, whether there is sufficient evidence to justify beginning an inquiry".

A spokeswoman for Mr Bercow declined to comment.

The incident came on the day an inquiry into allegations Mr Bercow bullied two former private secretaries, Angus Sinclair and Kate Emms, was blocked by MPs.

The Commons Standards Committee voted three to two against allowing Parliament's watchdog to investigate the allegations, which the Speaker has consistently denied.

He told MPs yesterday that he had been unhappy about a "badly handled" transport statement that had reduced time for other business in the house, including a Grenfell Tower debate.

"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,” explained Mr Bercow.

"Anyone who knows [Mrs Leadsom] at all well will have not the slightest doubt about her political ability and her personal character," he added.

Later, Mrs Leadsom spoke at the Commons despatch box, saying: "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," she added.