The SNP has launched its strongest attack yet on Kremlin "disinformation" just as its former leader hosted a Christmas special of his chat show on a Russian propaganda channel.

The party has long warned of the threat from President Vladimir Putin's campaign to sow international discord using both social media and TV stations like RT, which broadcasts the controversial Alex Salmond Show.

Now a senior MP - stressing that he was speaking for both the SNP and the Scottish Government - has backed Britain's hardline stance on such channels and drawn a clear line between the mainstream party and Mr Salmond.

West Dunbartonshire's Martin Docherty-Hughes said: "We firmly support the UK Government’s efforts in tackling Russian disinformation and propaganda."

Mr Docherty-Hughes was speaking just before a dramatic day in Russian-UK relations.

READ MORE: Mr Docherty-Hughes on Russian Propaganda in his own words

First Foreign Secretary Boris Johnson arrived in Moscow to tell his Russian counterpart there could be no "business as usual" between the two countries while the Kremlin continued its "destabilising activities in Europe".

Then it emerged that a man who had translated for Theresa May and the prime minister of Ukraine had been arrested in Kiev on suspicion of spying for Mr Putin.

And finally, in a Commons debate on Russian meddling in the West, a Brexiteer MP revealed that the Vote Leave campaign was aware of "a certain amount of odd-looking cyber activity" during the EU referendum campaign.

Digital experts have accused Russia of using social media accounts to support the election of Donald Trump in the US and the Leave campaign in UK.

Earlier this month it emerged that Russian-based Twitter accounts helped spread a false news story - first aired by a Kremlin-run agency - that the Scottish independence referendum had been rigged.

Mr Docherty-Hughes' remarks, in a Wednesday Westminster Hall debate on the future of Ukraine, were the clearest statement of SNP support for independent countries on Russia's borders worried about the 2014 annexation of Crimea and ongoing proxy, hybrid war in eastern Ukraine.

The MP accused Mr Putin of testing the West's resolve with what he called a "digital blitzkrieg", a campaign of hacking and jamming of cyber-infrastructure in Ukraine parallel to military action.

Alex Salmond interviewed on RT

HeraldScotland:

And - in a challenge to a core Kremlin aim of keeping Ukraine within its orbit - he backed Ukrainian aspirations for EU membership.

The SNP, eager to underline its pro-EU and pro-Nato credentials ahead of a second independence referendum, has been largely shunning Russian propaganda outlets seen as much a part of Mr Putin's military capability as spies or the "green men" soldiers in unmarked uniforms who seized Crimea.

A spokesman for First Minister Nicola Sturgeon earlier said Scottish ministers would not appear on Mr Salmond's show.

READ MORE: Alex Salmond reprises Rikki Fulton Rev IM Jolly character for RT Xmas show

Ms Sturgeon's predecessor and former mentor, however, has insisted he has editorial control over his programme, which is made by a firm called Slainte Media he owns and runs with another former MP, Tasmina Ahmed-Sheikh.

Russia experts, however, have warned that any high-profile collaboration with the channel will be seen globally as an endorsement for its cocktail of sometimes anti-establishment news about the West and routinely pro-establishment messaging about Mr Putin's regime and especially its actions in conflict zones like Syria and Ukraine.

A former minister on Thursday said British politicians, especially of the left, should stay off RT.

Martin Docherty-Hughes

HeraldScotland: Martin Docherty has a masters from GSA

Labour's Ben Bradshaw told the House of Commons: "It pains me to say there are still some of these useful idiots on the left in British and international politics.

"My message to them is that Russia is a nasty, nationalistic, ultra-conservative, corrupt kleptocracy. It's racist, it's homophobic, and it makes no secret of wanting to undermine our democracy."

Analysis: why Alex Salmond's Kremlin TV channel is an 'information weapon'

In a Christmas special of his show broadcast this week Mr Salmond laughed off claims that he is now a Kremlin stooge.

In a reprisal of his BBC Children in Need impression of the Ricky Fulton character IM Jolly, he said that "The Very Reverend Putin" had signed him up for a TV show.

He joked: "'Songs of praise?' I enquired. 'No,' said Mr Putin said, 'just the praise'."

Alex Salmond as IM Jolly

HeraldScotland:

Meanwhile, speaking ahead of his meeting with Russian Foreign Minister Sergei Lavrov, Mr Johnson said: "Our relations with Russia cannot be 'business as usual' whilst Russia continues to attempt to destabilise European states, including Ukraine.

"However, it is vital for international security that we do talk to each other, as the consequences of miscommunication or misunderstanding are grave."

Analysis: why Alex Salmond's Kremlin TV channel is an 'information weapon'

Prime Minister Theresa May left no doubt that she was not ready for a thaw in relations with Russia in her high-profile Mansion House speech last month, when she accused Mr Putin of using cyber-espionage and disruption to sow discord in the West and warned the Kremlin: "We know what you are doing. And you will not succeed."

Britain last week backed the EU decision last week to roll over sanctions imposed on Russia over its interference in Ukraine and continues to insist that Moscow must live up to the terms of the Minsk Agreement requiring it to cease support for armed separatists.

Mr Docherty-Smith stressed this is also the policy of the Scottish Government. His colleague Douglas Chapman, who has appeared on RT, echoed this, adding a call for civil recovery actions should be taken against Putin regime figures investing in the London property market.