Lord Hain exposed the retail mogul in the House of Lords yesterday after a court injunction banned the media from reporting the billionaire's name.
Sir Philip, chairman of the Arcadia group that owns chains including Topshop and Miss Selfridge, allegedly signed non-disclosure agreements (NDAs) with five members of staff who accused him of mistreating them.
In a statement issued after Lord Hain's speech, he said he "categorically and wholly" denied any allegations of "unlawful sexual or racist behaviour".
The businessman had initially remained anonymous after a court injunction was granted preventing the Daily Telegraph from naming him.
However, Lord Hain told the Lords he believed it was "my duty under parliamentary privilege to name Philip Green as the individual in question", saying the media had been prevented from publishing "the full details of a story which is clearly in the public interest."
The move divided opinion, with some lawyers accusing the former cabinet minister of pre-empting an ongoing legal case.
Defending his decision, Lord Hain told BBC Newsnight he had received "overwhelming support - particularly from women".
He said: "I believe it was the right thing to do. I considered it extremely seriously before I said it, as anyone who is using parliamentary privilege always does.
"I'm not disputing judges' responsibilities - that's a matter for the judiciary. I'm discharging my function as a parliamentarian. What concerned me about this case was wealth, and power than comes with it, and abuse, and that was what led me to act in he way that I did."
He added: "It is for others to judge whether I've been right or wrong but there's no point being in Westminster...if you never discharge that or deploy the precious rights of parliamentary privilege to be used extremely careful, with integrity and very responsibly."
Sir Philip is facing fresh calls for his knighthood to be withdrawn, echoing similar demands that followed the collapse of chain store BHS, which he previously owned.
Independent MP Frank Field, who chairs the Commons work and pensions committee and was highly critical of Sir Philip during the BHS scandal, said: "The charge sheet against the knighthood is growing.
"Parliament and the country have made their views clear on this matter. Ultimately it's a decision for the Honours Forfeiture Committee."
Mr Field said he had been contacted by a sixth person who alleged Mr Green had mistreated them and who wanted to speak out about their experience.
The veteran MP said he wanted to establish a mechanism in Parliament "through which the voices of victims of abuse can be heard" to ensure the House of Commons "stands up for people who have little money, against those who have much".
Responding to the allegations against him, Sir Philip said in a statement: "I am not commenting on anything that has happened in court or was said in Parliament today.
"To the extent that it is suggested that I have been guilty of unlawful sexual or racist behaviour, I categorically and wholly deny these allegations."
He added: "Arcadia and I take accusations and grievances from employees very seriously and in the event that one is raised, it is thoroughly investigated.
"Arcadia employs more than 20,000 people and in common with many large businesses sometimes receives formal complaints from employees. In some cases these are settled with the agreement of all parties and their legal advisers. These settlements are confidential so I cannot comment further on them."
Theresa May's spokesman declined to comment on Lord Hain's speech, saying: "The rules on parliamentary privilege are a matter for Parliament and how they exercise these rules is a matter for individual members."
But Conservative Party deputy chairman James Cleverly said Lord Hain's decision had shown "people must now realise that injunctions and super-injunctions are nothing more than a good way to part with large sums of money and a bad way to keep things secret".
The peer was also praised by Labour's Jess Phillips, who has campaigned extensively against sexual harassment.
She said he "did the right thing", adding: "It was brave and I doubt he took the decision lightly."
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