Senior SNP politicians are shunning Kremlin mouthpieces like TV station RT and radio and online giant Sputnik News.

The Herald already understands the party hierarchy now routinely refuses bids for interviews with the outlets, which slavishly back the government of Vladimir Putin.

The stance comes amid growing concerns that Scottish nationalists could be exploited by a propaganda machine seeking to equate the independence movement in this country with Russian-backed separatists in eastern Ukraine.

Some backbenchers and activists do continue to engage with the Russia Today or RT, formerly Russia Today, and Sputnik News, which recently opened its UK HQ in Edinburgh.

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However, West Dunbartonshire MP Martin Docherty-Hughes, pictured above, urged party supporters to consider messages from Kremlin-backed media sources like Sputnik news carefully before reading or sharing them on social media.

Docherty-Hughes said: "It is often tempting to think that the messages put forward by these channels are progressive, but it may be worth asking if the sources funding the likes of Sputnik News really do share your views.

"These are news sources directly funded by a regime which has absolutely no problem with abusing human rights and minorities, and most certainly would not tolerate a nationalist movement like our own within its own borders."

Sputnik News was formed from the old Voice of Russia and RIA Novosti news agency. HeraldScotland:

It broadcasts and publishes in numerous languages and is - officially - designed to counter what is founder, Dmitry Kiselyov calls "aggressive Western propaganda".

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Some Scottish nationalists and Labour supporters - who share a narrative about mainstream media bias - have been courted by the Kremlin channels.

Former First Minister Alex Salmond and current Labour leader Jeremy Corbyn have both previously appeared on RT, which is available in English as part of most British satellite and digital television packages.

Mr Salmond used one lengthy RT interview filmed in Shetland in 2013 to question the ability o the BBC to report on the independence referendum.

Mr Corbyn, before his election as leader, was a fairly regular contributor to RT.HeraldScotland: Jeremy Corbyn says Labour wants the UK to remain part of the European Union

He even encouraged his Twitter followers to watch the channel, saying its international news was more "objective" than western outlets.

This sparked concern among Russia watchers, who were deeply sceptical about RT's coverage of the complex conflict in eastern Ukraine. Historian Anne Applebaum called the then Labour backbencher one of a "long line of useful idiots".

The Labour leader is no longer a regular on RT.

Russian foreign-language media such as RT and Sputnik have a policy of airing views they believe undermine western institutions.

This includes encouragement for independence movements across Europe of a kind that, in Russia, would be considered criminal.

There has been a specific effort in Russian media and political circles to equate Scotland’s 2014 referendum with a plebiscite in the annexed Ukrainian territory of Crimea.

Background: How Russia sought to equate Scotland's referendum with Crimea

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The House of Commons recently heard evidence that RT was part of a propaganda strategy in the West.

Former BBC correspondent and NATO representative Mark Laity said: "If telling the truth helps, they will tell the truth.

"If telling a lie helps, they will tell a lie.

"The editor of RT is famously quoted as saying there is no such thing as objectivity, so for them, I would say that the Russian approach to information really is operational.

"To them, telling the truth or telling a lie is about the effect."

The Kremlin and Kremlin media outlets were deeply hostile to Scottish independence until they saw opportunities to draw comparisons with events in eastern Ukraine and Crimea.

Last year a pro-Kremlin organisation invited Scottish nationalists to a "separatist summit" in Moscow.

The SNP urged a boycott, saying it had no wish to meet with the leaders of self-proclaimed republics of Donetsk and Lugansk.