Bullying in the House of Commons stems from a culture where "some people don't matter", an MP has admitted.

Jess Phillips , Labour MP for Birmingham Yardley, said some MPs get used to the idea that Commons staff or their researchers are there to make their coffee, write their speeches and even to hold open the door.

And this helped explain why there had been allegations that some MPs have bullied staff, she said.

It follows an investigation by BBC Two's Newsnight which found claims that MPs had bullied and harassed House of Commons officials, known as clerks.

Newsnight reported that that women working in the Commons said they had been pushed against walls, forcibly kissed, groped and slapped by MPs.

Ms Phillips said: "We could do better, have better policies, tougher action (or any action at all) against bullying but the problem is the culture. A culture where some people matter and some people don’t."

Writing in the Huffington Post, she said the arrogance of some MPs threatened democracy.

She said: "We live in dangerous times and our democracy is under threat. We shouldn’t be providing ammunition to those who seek to harm us.

"Authoritarian behaviour by those in our democracy is music to the ears of authoritarian leaders around the world."

Ms Phillips said MPs should acknowledge that they depended on help from many other people in order to do their jobs, and suggested that MPs who abuse Commons staff should forced to see if they could survive without them.

"My colleagues who have bullied staff have no reason to think that they are any better than the women who have come forward, in fact they are no where near as good.

"Perhaps the real punishment would be if we took away all of their staff and all staff support in Parliament - even, God forbid, made them make their own coffee. See how long your mandate lasts then, mate."

Commons Speaker John Bercow has denied bullying

Downing Street has said that any complaints of bullying in Parliament should be "fully investigated", following allegations of abuse of staff by MPs including Speaker John Bercow.

Mr Bercow denied bullying behaviour, while a House of Commons spokesman said it was a "responsible and supportive employer" and did not tolerate "bullying or harassment of any kind".

But a Downing Street spokesman said that Prime Minister Theresa May regarded the allegations as "concerning".

"The Prime Minister is clear that there can be no place for bullying or harassment of any kind at Westminster, and everybody should be free to work in an environment that is safe and respectful," said the Number 10 spokesman.

"If any complaints are made, they should be fully investigated."

He added: "With regard to the Speaker, I note the allegations are being contested, but I think these are concerning allegations and there can be no place for bullying or harassment of any kind. If complaints are made, they need to be investigated."

Asked whether Mrs May had confidence in Mr Bercow as Speaker, the spokesman said: "Yes."

Newsnight conducted dozens of interviews and reviewed internal parliamentary human resources documents as part of its investigation.

Allegations were also made about Shropshire MP Mark Pritchard and Staffordshire MP Paul Farrelly.

Clerks told the programme that Mr Pritchard (Con The Wrekin) was "particularly nasty to those he felt were below him" and was "known for having a dreadful temper".

He allegedly swore at an official, telling her "you haven't got a f***ing clue what you're talking about".

Mr Pritchard told the programme: "I understand, over the past several years the House authorities have addressed numerous complaints about MPs, but they have also informed me they have no record of any complaints against me, and if they had, I would have been notified."

Conservative MP Mark Pritchard

Mr Farrelly, a member of the Culture, Media and Sport Select Committee, was the subject of a formal complaint under the House's Respect policy in 2012 in relation to his treatment of clerk Emily Commander, the programme said.

The inquiry conducted by House official Edward Wood concluded there had been "an abuse of power or position, unfair treatment and undermining a competent worker by constant criticism", adding "the conduct was offensive and insulting".

But the House of Commons Commission, a panel of MPs chaired by the Speaker, could not reach a decision on what to do, Newsnight said.

Mr Farrelly (Lab ewcastle-under-Lyme) told Newsnight: "In 2012 allegations were made about me having bullied a clerk to the Committee during the compilation of the phone hacking report.

"These allegations were investigated and not upheld.

"Despite this, I apologised if I had inadvertently upset the clerk who had suffered stress.

"The policy under which they were investigated was considered to be so unfair to those complained about that it was immediately withdrawn and replaced by another policy."

A House of Commons spokesman said: "We take the welfare of our staff extremely seriously, and strongly reject any claims to the contrary.

"It is a grotesque exaggeration to suggest that members of the House of Commons service work in a 'culture of fear' in relation to dealing with bullying and harassment by MPs.

"The House of Commons takes pride in being a responsible and supportive employer and does not tolerate bullying or harassment of any kind."