Operation Midland: Tom Watson told to apologise for abuse claims

Mr Proctor, the last living person under investigation by Operation Midland, launched a scathing attack on Labour's deputy leader, accusing him of making 'self-serving' comments about the Metropolitan Police's investigation into claims that several young boys were sexually abused by high-profile figures.

He said the West Bromwich East MP, along with fellow Labour MP John Mann and London mayoral candidate Zac Goldsmith 'should hang their heads in shame' for commenting on claims that a VIP child sex ring ran out of Westminster.

Mr Watson has declined to comment further on the issue. The Operation Midland inquiry cost in excess of £1.8 million and ended with no charges being brought.

It comes after former MP for Basildon and Billericay Mr Proctor accused the Met and other police forces of being 'the leakiest of bodies' after details of their investigation, including a search of his home in Pontefract, West Yorkshire, appeared in the media.

The resulting coverage 'engulfed me and destroyed my life', he said, as he issued a plea to Parliament to 'redress the imbalance in the law in favour of people alleging sexual abuse'.

Mr Proctor, aged 69, has previously revealed he faced allegations of murder, rape and the abuse of young boys as part of a group of men who abused children in the 1970s and 1980s.

He has always staunchly maintained his innocence during the 16-month probe, which was sparked by allegations made by a solitary witness known as 'Nick'. He claimed he was abused for nine years from 1975, when he was seven, to 1984. His identity has never been made public.

In an open letter Mr Proctor wrote: "The likes of Tom Watson, John Mann (who described me on the day of my house search as 'the first of many') and Zac Goldsmith should hang their heads in shame – I doubt they will do so as by their words they have shown themselves to be the antithesis of their sobriquet in parliamentary terms, 'honourable' men.

"I only hope in their lives they never face the turmoil that their varying degrees of encouragement to fantasists and the police has caused me this past year."

Numerous high profile figures were drawn into Operation Midland, including Sir Edward Heath, prime minister between 1970 and 1974, former home secretary Lord Brittan. and the then commander in chief of UK land forces, General Lord Bramall. All were cleared.

Mr Watson caused shockwaves in October 2012 when he told the Commons that he had evidence that there was a 'powerful paedophile network linked to Parliament and Number 10'.

Detectives launched Operation Fairbank to probe the claims of child abuse and later Operation Fernbridge, looking at the former Elm Guest House in south west London, where it was rumoured children had been molested by high profile figures.

However little firm progress was made in lifting the lid on the so-called parliamentary paedophile ring.

The Met launched Operation Midland after it was approached by 'Nick', who made a series of claims, including that three boys were murdered by members of the supposed paedophile ring.