Britons in Russia are preparing for a worsening of relations with their Russian compatriots, despite so far feeling unaffected by their nations' recent diplomatic fallout.

Expatriates living in Moscow said the expulsion of 23 Russian diplomats in the wake of the poisoning of former MI6 double agent Sergei Skripal - and Russia's subsequent tit-for-tat response - had yet to impact them, although some did worry about a potential "trickle-down effect" if political tensions continued to rise.

One man, who wished only to be identified as Mark, said he has become more cautious about speaking English in public and even contemplated claiming to be Irish to avoid conflicts.

He said: "I'm not sure I'm important enough or prominent enough on the Kremlin radar to be immediately affected by the current situation, but I'm somewhat worried that if the situation worsens, which I expect it to do, there could be a trickle-down effect that has an impact upon me.

"On a day-to-day level, I have started trying to be more inconspicuous in public - not that I was especially conspicuous before - but I'm having fewer English phone conversations, and holding English book covers down on my lap on the metro."

A statement published on the Foreign and Commonwealth Office website last week warned Britons of the "possibility of anti-British sentiment or harassment at this time", and asked British nationals to "remain vigilant" and avoid protests, demonstrations and commenting publicly on political developments.

But another British resident in Russia, who wished not be be identified, said he was so far unconcerned by the warning.

"There's absolutely no signs of tension with the local Russian population," he said.

However, Britons were wary that the current "political battle" could escalate further, he added.

Several interviewees told the Press Association their main concern was the potential for a more dramatic decline in relations, such as that seen in the wake of the 2014 annexation of Crimea, which prompted a drop in the value of the ruble and overseas wages.

But one British director at a financial services company in Moscow, who also wished not to be identified, said even a relatively acute increase in sanctions and counter-sanctions such as those imposed by Vladimir Putin on foreign food imports in 2014 was unlikely to have a significant impact on Britons without a far deeper fallout.

He said: "Nothing's really been done which affects your average Russian on the street.

"It's very easy to forget that for me, for example, it's disastrous not being able to buy Parmesan or Gorgonzola or whatever, but for your average Russian outside of Moscow, they really don't care about that."

He added: "For them what's much more important is the message that 'we're strong, we're defending ourselves against this perceived enemy' [of other European powers]."

The UK national security council is expected to meet in the coming days to discuss Russia's current response to the situation, and foreign secretary Boris Johnson accused Russia of trying to conceal "the needle of truth in a haystack of lies" as he arrived for a meeting with his EU counterparts on Monday.

Mr Skripal and his daughter Yulia remain in a critical condition in hospital after being exposed to the nerve agent Novichok in the Wiltshire city of Salisbury on March 4.