A decision not to prosecute Lord Janner over allegations of historic child sex abuse will be overturned after an independent QC reviewed the case, according to reports.

The former Labour MP has severe dementia but it was expected to be officially announced in the next week that the allegations will be aired in court, the Daily Mail said.

The Crown Prosecution Service announced in April that it would not charge the 86-year-old but the following month it said it would review the controversial decision.

An independent QC was reported to have now recommended that the decision by Alison Saunders, the Director of Public Prosecutions, should be overruled.

Lord Janner has been accused of a string of historic child sex abuse allegations during the 1960s, 1970s and 1980s. He was MP for Leicester West for 27 years.

The Director of Public Prosecutions said the original decision not to proceed with court action against the politician was due to his ill health.

The Daily Mail reported that the evidence could be tested in a criminal court even if he was too unwell to attend, in a "trial of the facts".

His family has repeatedly denied he is connected to any wrongdoing.

Simon Danczuk, Labour MP for Rochdale who has campaigned for the alleged victims of abuse, welcomed the apparent overturning of what he said was a "cold decision" by the DPP.

He said: "I am hopeful we will get the sort of result we have been campaigning for, which is some form of justice, probably in the shape of a trial of the facts.

"I welcome that as it gives the alleged victims the opportunity to talk about their experience and what they have gone through and it provides some accountability.

"It does create a problem for Alison Saunders.

"She made a decision that really lacked any emotional understanding."

He added: "I would describe that as a cold decision."

Should the peer be prosecuted, there was a question whether he should still be in the House of Lords, Mr Danczuk said.