Nadine Dorries: I have become accustomed to the grubby world of British politics. But nothing could prepare me for this

It came as a shock on Friday to discover I was one of the subjects of Damian McBride's failed smear operation – a shock that the office of No 10 Downing Street had reached a moral depth few would have imagined possible.

The allegations regarding myself are 100 per cent untrue. Totally and completely fabricated.

I have worked in this grubby world of politics for quite some time now. I am used to exaggeration and spin. The media do it best, as demonstrated during the recent MPs' expenses fiasco. No one could have had more dirt thrown at them from the other team than I did during the abortion debate. However, to have stories completely dreamt up in the Prime Minister's office by a civil servant, paid for by the taxpayer, is breathtaking.

We are post-G20, in the middle of a banking and economic crisis, plummeting to the depths of recession. Unemployment is rising, civil unrest beckons, teachers are voting to take unlawful industrial action, Iran is almost nuclear-ready, we are at war in Afghanistan and Iraq, and in the midst of all of this, the Prime Minister's right-hand man is drafting emails attempting to assassinate the reputations and careers of Conservative politicians.

Damian McBride – also known as McPoison – reports directly to the Prime Minister, no one else. He takes his instruction from the Prime Minister and works within the Prime Minister's private office in the heart of 10 Downing Street.

Are we really expected to believe that the Prime Minister knew nothing of this?

As our country's economic standing worsens day by day, and it becomes nigh-impossible for the Labour Party to make itself re-electable, the desperate tactic appears to be to diminish the standing of the Conservatives and make Labour the least unattractive option. Is this how a "son of the manse" runs his office, his staff and the country?

McBride has claimed the scalps of more Labour MPs and ministers than he has Conservative frontbenchers. He is almost universally disliked in the Labour Party. His resignation does not close down the story because McBride and the PM were as one. The Government was spinning desperately yesterday, attempting to distance the PM from McBride. That just isn't doable: they have been glued at the hip since their early days at the Treasury. There were others in the marriage too: blogger Derek Draper, who pathetically claimed McBride shouldn't resign and that the emails only reached the public domain because blogger Paul Staines hacked into his computer. I suppose that story provided the weekend's little light relief. Draper needs to see a psychotherapist.

The minister Tom Watson, whose desk was right next to McBride's, is reputedly the PM's Commons spy, scuttling to No 10 with gossip on Labour MPs. He is a huge disappointment: naively, I had taken him at face value and liked him.

To the Prime Minister's left, right and at his feet, the bully boys sit around the fire wondering whose life and career they can destroy next. And whilst they fiddle and concentrate their efforts on ensuring Gordon Brown retains office at whatever cost, Rome burns.