Labour MP John McDonnell has refused to apologise for quoting a constituent who called for Wirral West MP Esther McVey to be lynched and branded the employment minister a "stain of inhumanity".

The Hayes and Harlington member faced further calls to say sorry in the Commons earlier this week, but insisted he had nothing to apologise for.

He also referred to the "suffering" caused by Ms McVey, who represents Wirral West, and accused her of trying to make herself a victim.

Raising a point of order, Conservative Mary Macleod (Brentford and Isleworth) asked: "Would you be able to clarify that process exists in the situation where the member for Hayes and Harlington refuses to apologise to the member for Wirral West for quoting someone referring to her saying 'lynch the bastard'.

"If he didn't agree with remarks by others, which were in effect inciting violence against a female MP, why on earth would he repeat them to another audience? I had hoped he would apologise before this House dissolves but no apology has been forthcoming."

Mr McDonnell replied: "This has been raised before. It was accepted by the House that in no way would I ever encourage violence or support violence against an honourable member.

"Therefore there is nothing for me to apologise for.

"If a constituent shouts something out to an MP that is a matter for the constituent.

"This is the honourable member for Wirral West trying to make herself into a victim in this issue.

"I was simply putting it in the context of the suffering that has been caused by the honourable member for Wirral West."

He was interrupted a number of times by Deputy Speaker Eleanor Laing, who told him to stick to the point.

But he continued: "The substance of the matter is there is nothing to apologise for and I hope the electorate on May 7 will remove the stain of inhumanity."

His remarks were met with cries of "say sorry" from the Tory benches.

Ms Laing said: "It is disappointing that a matter like this should have to come before the House.

"What honourable members say outside this place is not a matter for the chair.

"I would however strongly clarify that it is incumbent upon all members of this House whether within this chamber or elsewhere to act with courtesy to one another and indeed to everyone else whom they might encounter.

"I understand your (Ms Macleod's) particular concerns about reported comments suggesting violence whether it is seriously intentioned or not.

"I'm quite certain ... that no honourable member would wish to be associated with such comments.

"I urge honourable members who are concerned in this matter to consider that apology is not backing down, apology is a courteous way of settling a matter.

"One would hope that honourable members of this House would wish to act always with such courtesy."

This is not the first time the matter has been raised in the House of Commons.

In December, Mr McDonnell and Ms McVey were told by Deputy Speaker Lindsay Hoyle to end the "personal attacks" after they clashed over the issue.

The Daily Mail reported in November that Mr McDonnell repeated comments about Ms McVey during a comedy night attended by left-wing activists and fellow Labour politicians, which had been organised by the Stop the War Coalition on Remembrance Sunday.

He reportedly said: "I was up in Liverpool a fortnight ago where Alec McFadden, one of our (union) organisers, launched the Sack Esther McVey Day on her birthday.

"I spoke at a packed public meeting ... there was a whole group in the audience that completely kicked off quite critical of the whole concept, because they were arguing 'Why are we sacking her? Why aren't we lynching the bastard?'"

After the issue was raised in the Commons by Tory Margot James (Stourbridge) in November, Mr McDonnell claimed a "choreographed exercise" between the Daily Mail and Conservative central office led to the remarks emerging on the same day as a major speech by Labour leader Ed Miliband.