No 10 today slapped down Kremlin claims of a 'witch hunt' against President Vladimir Putin with jibes about Russia's weak economy and Britain's free press.

In an extraordinary escalation of tensions between London and Moscow, Russia said the UK government was 'panicking' and trying to drive a wedge between US President-elect Donald Trump and Moscow.

The furious attack came as fresh accusations surfaced about Moscow's meddling, with claims - angrily denied by Mr Trump - that the Kremlin has assembled a dossier of 'dirt' against him.

But Theresa May's official spokeswoman dismissed the claims today.

Theresa May's official spokeswoman dismissed a Kremlin attack on Britain today, slamming Russia's economy and hobbled press

She said: 'If you want to look at the record of the UK Government in recent years and make comparisons with the Russians, you might think about negative economic growth in Russia and the UK being one of the fastest-growing major economies in the world?

'How many times the UK has consistently advanced and supported UN Security Council resolutions on Syria - I think Russia was meanwhile vetoing them?

'The fact that we have freedom of expression and a free press in the UK who will choose what they report?

'Those are just the realities of the UK Government versus the Russians. You ought to look at what the UK Government's record of actions are and what the Russian record of actions are.'

US officials allegedly included a two-page synopsis of 'kompromat' – Russian for compromising material – as part of their security briefing for Trump last week.

The material was reportedly based on memos compiled by a former British intelligence agent.

The Russian embassy in London said the government was 'panicking' and trying to drive a wedge between US President-elect Donald Trump and Vladimir Putin

The Russian embassy accused the government of a witch hunt on its Twitter feed and website

What is believed to be the 35-page document itself was published by Buzzfeed, which pointed out that it contained errors.

Little of its contents can be independently verified, while there has been no official confirmation of the details of the briefing and Donald Trump has branded the claims as 'fake'.

The document claims Russian sources told the operative that they had extensive material on the now president-elect - including a secret film of him in the suite where President Obama stayed in Moscow, watching prostitutes committing degrading sex acts on the bed where the president slept.

Trump himself - who is due to be formally installed as president in nine days - has already dismissed the claims, tweeting: 'FAKE NEWS - A TOTAL POLITICAL WITCH HUNT!'

American intelligence agencies have also accused Russia of directly interfering in the presidential election by hacking the Democrat computer network and leaking damaging material about Hillary Clinton.

Foreign Secretary Boris Johnson yesterday that Russia was 'up to all sorts of very dirty tricks'.

Donald Trump has dismissed claims over his ties to Russia and said allegations of a dossier of 'dirt' on him are fake

The angry denial came in a post on the billionaire tycoon's Twitter feed - although he did not specify what he was referring to

Mr Johnson told the Commons yesterday that he had spoken to high profile congressional leaders as well as Mr Trump's advisers about the issue of Russian dirty tricks.

'The point that we have made to the incoming administration, and indeed on Capitol Hill, is just this: as I said earlier, we do think that the Russian state - the Putin Kremlin - is up to all sorts of very dirty tricks, such as cyber-warfare,' he said.

'But it would be folly for us further to demonise Russia or to push Russia into a corner, so a twin-track strategy of engagement and vigilance is what is required.'

Theresa May is preparing for her first meeting with the incoming US commander-in-chief when she visits Washington in the coming weeks.

Boris Johnson (pictured speaking to senior Republican Bob Corker in Washington this week) said he had told Trump's aides Russia was up to 'very dirty tricks'

Part of the document, allegedly compiled by a former British intelligence agent, is seen above. Click here to see the full document first published by Buzzfeed

In a ranting press release on its website, the Russian embassy claimed the UK authorities were attempting to undermine the EU referendum result by claiming it was tainted by foreign influence.

It directly criticised former MI6 chief Sir Richard Dearlove for standing down from a Cambridge University intelligence forum over fears of Kremlin influence.

The embassy also suggested the UK was being hypocritical when criticising alleged Russian war crimes in Syria, highlighting the use of British-made banned cluster bombs in the civil war in Yemen by a Saudi-led coalition.

And it claimed Britain had once again 'outsourced' the fight against extremism to Russia.

'Ultimately, defeating Nazi Germany was 'outsourced' to the Soviet Union,' the post said.