Labour deputy leader Tom Watson has been invited to give evidence to the Commons Home Affairs Committee over his pursuit of sex abuse allegations against the former Conservative cabinet minister, Lord Brittan.
The committee, chaired by Labour MP Keith Vaz, announced the decision in a statement on Tuesday afternoon.
Watson has rebuffed Tory calls to apologise to the widow and family of the peer, who died in January without being told he had been cleared of a rape allegation.
In a blog on The Huffington Post, Watson accepted he should not have repeated the comment of an alleged sex abuse survivor that the peer was "close to evil".
But he insisted he was he was doing his duty by passing on information and pressing for an investigation.
The Crown Prosecution Service (CPS) found in July 2013 that there was not enough evidence for a prosecution, but the decision was never passed on to the peer.
The case was reopened last year after Watson wrote to the Director of Public Prosecutions and police later interviewed Lord Brittan under caution, when he was seriously ill.
The BBC reports Crown Prosecution Service claims the police interviewed Lord Brittan before the CPS received the letter containing allegations from Watson.
The Prime Minister said parliamentary panels were "quite rightly going to ask him some questions" and that the Labour MP should "examine his conscience about whether he's said enough so far".
Demands for an apology - including from the peer's brother - came after a senior Scotland Yard officer wrote to Lord Brittan's widow to apologise for failing to tell the family before the peer's death that he had been cleared of allegations that he raped a 19-year-old woman in 1967.
Tory Sir Nicholas Soames described Mr Watson as "the witch-finder general" and said the debate over historic sex abuse by Westminster figures was "running out of hand".