MPs will pay a heavy price for harbouring paedophiles in their midst.
As I was I was making my way from the House of Commons on Monday night after a late vote a Tory minister stepped out of the shadows to confront me. I'd never spoken to him before in my life but he blocked my way and ushered me to one side.
He warned me to think very carefully about what I was going to say the next day before the Home Affairs Select Committee when I'd be answering questions on child abuse.
'I hear you're about to challenge Lord Brittan about what he knew about child sex abuse,' he said. It wouldn't be a wise move, he advised me.
'It was all put to bed a long time ago.'
He warned me I could even be responsible for his death.
We looked at each other in silence for a second. I knew straight away he wasn't telling me this out of concern for the man's welfare.
There was no compassion in his voice.
As politicians made their way out of Westminster, I had no doubt that other conversations like this were taking place.
Indeed, this was confirmed when I spoke to other members of the Select Committee the next day.
They'd been paid similar visits. Phone calls had been made. Members who'd previously indicated they would ask me who I thought knew about the VIP child abuse ring at the notorious Elm Guest House in southwest London were suddenly silent.
During the committee hearing later that day, one MP asked if pressure had been put on me to keep quiet about suspected child abusers. I nodded. Yes, it had. The MP pursued it no further.
The next day, several people said to me it was surprising no one on the committee had pursued this answer, demanding to know where the pressure was coming from.
The answer is simple: it is because they all knew.
After being neglected for far too long, child abuse is now reviled at all levels of society. It generates disgust and anger.
I welcome the Home Office announcement yesterday that a senior lawyer is to investigate claims that a paedophile sex ring at Westminster has been covered up. But it is no substitute for the full scale public inquiry needed to establish the truth once and for all.
Recent events have led me to the inescapable conclusion that in politics, particularly when the focus is on members of parliament guilty of abusing children, it frequently generates indifference. That's not to say all politicians have a blind spot where this terrible crime is concerned.
There are some great campaigners across all parties working hard to protect children – as evidenced by the 130 MPs who have signed up to a call for a public inquiry into historic child abuse.
But among the higher echelons of party politics, where the real power resides, my impression is that there is little appetite to confront the abusers in their midst. Quite the opposite. The mood is defensive, the approach is dominated by silence. 'Move along, nothing to see here,' or 'what's the point in raking all that up old boy?' is the attitude I have seen time after time.
A few months ago police officers came to visit me to discuss an investigation into a current parliamentarian accused of horrific child abuse. I listened to some of the details of the alleged crimes and my stomach churned.
Did I think it was likely that their inquiries would be met by political interference, the police asked?
I looked at them in utter disbelief. How can the police put a Cabinet Minister behind bars for lying about speeding points but be worried they couldn't properly investigate someone for child abuse?
The incident spoke volumes about the mindset that pervades politics. This kind of obstructive, 'Look the other way, sweep it under the carpet' thinking threatens to drag politics to new depths of public hate.
I believe we're on the verge of a Savile-like scandal sweeping through Parliament. Yet, for most people at the top, this prospect is not even on their radar. They're completely impervious to it.
If the political classes thought the expenses scandal was the worst nadir politics could experience in terms of public opprobrium they should think twice.
Once the idea that paedophiles have been lawmakers gains wider traction and people start to think political parties have knowingly harboured paedophiles then our parliamentary democracy will suffer an enormous, near fatal blow, the likes of which it will take years to recover from.
That 's why it's so important that political leaders quickly get on the front foot where this issue is concerned. Grasp the nettle, order a Hillsborough-style inquiry into historic abuse and confront the failings of the past.
Let victims be finally heard. Nick Clegg has refused to investigate who knew about Sir Cyril Smith's appalling paedophilia in his party and it has cost the Lib Dems dear. But this problem is not exclusive to his party.
The Tories have yet to properly face up to the abuse of Margaret Thatcher's aide Sir Peter Morrison, outed by fellow Tories such as Edwina Currie as a paedophile after he died.
Equally, there are potentially problems on the horizon for Ed Miliband after police recently searched Greville Janner's office as part of an investigation into alleged child abuse committed by the Labour politician.
David Cameron's former senior aide Patrick Rock is now facing trial over child abuse images and the former Liberal president Des Wilson has recently spoken about a Liberal MP who liked attractive boys and frequently had to be rescued from trouble after being picked up by the police.
Against this unedifying backdrop, the spectre of former Home Secretary Leon Brittan's calamitous handling of a paedophile dossier given to him by his fellow MP, the late Geoffrey Dickens, looms large.
This is arguably the most damaging incident yet, given that the dossier is said to have named Jimmy Savile, Cyril Smith and Establishment paedophiles and wasn't acted on.
After previously denying all knowledge of the dossier, Brittan's muddled statements last week acknowledging he had indeed received a dossier and then confirming that it had disappeared will only make the public suspicious of another cover up to protect high society paedophiles.
'I know exactly what I am up against,' said Mr Dickens at the time, 'for I know that within the Establishment there are those who would not wish to see a change in the law.'
Last week, Mr Dickens's granddaughter Louise told me her grandad had been betrayed by Lord Brittan, who was Mr Dickens's parliamentary colleague and someone he regarded as a friend.
'My grandad was determined to do the right thing, he wanted to give abused children a voice and the Home Secretary dismissed his work,' she said.
'He was years ahead of his time,' she says of Mr Dickens and I believe she's right.
Only now is the full horror of what he warned of about to start sinking in. The NSPCC estimate that one in 20 children have been sexually abused. Thousands of children will never speak out against their abusers because they don't think anyone will believe them.
And so they carry it with them for the rest of their lives. It doesn't have to be like this. We can do a lot better job of protecting children. But it won't happen without political leadership. And nothing will really change until Parliament faces up to the scandalous abuses of power within every party that have ruined lives.
