Christopher Steele, the ex-spy behind the Trump dossier, has broken his silence 18 months after his incendiary claims emerged

The former spy behind the 'dirty dossier' on Donald Trump has spoken of the duty of speaking 'unpalatable truths to power'.

Christopher Steele wrote a report which made wild claims that Trump ordered prostitutes to carry out 'degrading sex acts' including a 'golden shower' in a Moscow hotel while secretly filmed by the Kremlin's secret police.

Mr Steele went into hiding after the claims emerged last March, sparking scandal around the world and a storm of controversy in Washington DC.

He has finally broken his silence this week after he was named among the world's 100 most influential people by Vanity Fair magazine.

Steele wrote to the magazine, insisting there is a duty in speaking 'unpalatable truths to power' and praising those who speak out 'often at great personal cost'.

In a thinly veiled attack on Donald Trump, he claimed 'governance is so distorted and one-sided' in the US.

Mr Trump trashed the report, leaked early last year, saying: 'Sick people put that c**p together'

The letter, reported by Sky News, states: 'In these strange and troubling times, it is hard to speak unpalatable truths to power, but I believe we all still have a duty to do so.

'I salute those on your list, and otherwise, who have had the courage to speak out over the last year, often at great personal cost.

'At a time when governance is so distorted and one-sided, as I believe it currently is in the United States, the media has a key role to play in holding it accountable.'

After the dossier was leaked and published, Mr Trump claimed 'sick people put that c**p together' and called the dossier 'fake' and 'phony'.

The President even suggested that US secret services had leaked the document to damage his reputation before his inauguration.

He debunked the 'golden shower' claim by saying: 'Does anyone believe that? I'm a germophobe'.

Vanity Fair is currently holding a 'New Establishment Summit' in LA for those named in the list, but Mr Steele said he cannot attend.

He wrote: 'Sadly, in the present legal and political situation I am unable to do so, but I sincerely hope and trust that these circumstances will change soon.'

Mr Steele spied in Moscow in the 1990s and is believed to have been one of Britain's most senior intelligence officers in Russia as the Soviet Union collapsed.

After leaving the service he formed Orbis Business Intelligence, a London-based firm which gathers 'strategic insight and intelligence' for corporate clients, including helping the FBI uncover corruption at FIFA.

Steele's work led to a lucrative deal to dig for dirt on Trump's dealings with Russia, and he was paid Steele paid $168,000 by US-based company Fusion GPS.

Fustion had been paid $1.8million via lawyers representing the Democrats and the Hillary Clinton campaign.