When Theresa May set Vladimir Putin a deadline by which to explain how a nerve agent developed by the Russia military came to be used on the streets of Salisbury, she must have had an inkling that no explanation was likely to be forthcoming.

Sure enough, the deadline came and went; and the closest Russia has come to a concession is to say (via the Twitter account of its embassy in the UK) that it will only respond once it receives a sample of the chemical substance used in the attack on Sergei and Yulia Skripal. Moscow continues, nevertheless, to deny any involvement.

This has left the Prime Minister in a sticky – if hardly unanticipated – situation. Having made clear that the Government believes it is “highly likely” that the Russian state was responsible for the attempted assassination, she has been forced to figure out how best to back up her strong words with decisive action.

The balancing act she must perform is undoubtedly a difficult one and will play out over a considerable period. If ministers are as confident as they appear that Moscow is to blame (directly or indirectly) for the release of weapons-grade chemicals on British soil, the response must of course be robust. On the other hand, there appears to be a seeping recognition that tension between Russia and the UK could easily spiral out of control.

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The expulsion of 23 Russian diplomats, confirmed today, will almost certainly provoke a tit-for-tat riposte. Targeted sanctions against Russian state officials or individuals suspected of working to the Kremlin’s orders, will also, it appears, be forthcoming. This too may well incite a response in kind. And so it may go on.

One of the other options which remains on the table is more intriguing: the banning of the RT television channel (formerly known as Russia Today), which is funded directly by the Russian government. During Monday’s Commons debate on the crisis, Chris Bryant, Labour MP for Rhondda, raised the possibility and the Prime Minister pointedly did not rule it out, although it was not among the measures outlined today.

Other MPs have made clear their feelings about RT clear. Phil Wilson described the channel as a “propaganda mouthpiece for the Russian state”. John McDonnell has called for Labour MPs no longer to appear on RT programmes.

Over the years, politicians of all stripes have appeared on RT. Some may have taken the view that any opportunity to speak out in the media is worth taking. Others might have been reassured by the channel’s regular claims about editorial freedom or its stated mission to provide “an alternative perspective on major global events”.

Critics have long argued that the idea of RT being anything other than an instrument of propaganda is nonsense. And while the channel does an impressive job of looking professional – covering as it does all manner of global events – it has been publicly rebuked by the regulator, Ofcom, for misleading viewers about, among other things, the conflict in eastern Ukraine and claims that the BBC staged the use of chemical weapons by the Syrian government. Some RT staff have quit in protest at alleged political interference.

Russian Ambassador to the UK says the British Government response to Salisbury is 'absolutely unacceptable and we consider this a provocation'

Still, if few would doubt that RT is to a greater or lesser degree a tool of the Kremlin, banning it from broadcasting in the UK would be a mistake.

In order to end RT’s UK operations, Ofcom would have to determine that RT is not fit and proper to hold a broadcasting license. This is not as simple as it sounds and would – fairly or not – allow Moscow to raise questions about Ofcom’s own independence, since it would be seen to be acting in response to political pressure.

That in turn plays into the broader paradox that shutting down a propaganda network will only serve to fuel one of Moscow’s favoured propaganda lines: that the west talks the talk about democracy and free media, but fails to walk the walk.

RT’s average daily reach is only about 150,000 people across the UK. It is not a mainstream channel. MPs would be quite within their rights to conclude that they are better off not appearing on its shows. But any moves to encourage the revocation of RT’s license would be almost certain to backfire badly.