Russia said it was expelling a British diplomat for alleged spying as tensions between London and Moscow rose after Ukraine’s recent use of British weapons to strike deeper into Russia.

The FSB, Russia’s domestic intelligence agency, announced on Tuesday that it had acted on documents accusing a British diplomat of engaging in “reconnaissance and subversive activities that threaten the country’s security”.

The FSB claimed that the British diplomat “intentionally provided false information when applying for entry into Russia, thereby violating Russian law”. Russian media reported that the diplomat had been given a two-week deadline to leave the country.

According to the FSB, the British diplomat, whose photo was splashed across Russian TV news bulletins, was a replacement for one of six UK diplomats expelled in August, also over accusations of espionage. The British Foreign, Commonwealth and Development Office (FCDO) said at the time that the accusations were baseless.

The Russian foreign ministry said that it had summoned the British ambassador in Moscow, Nigel Casey. There was no immediate comment from the FCDO.

Relations between Britain and Russia plunged to a new low last week after Britain agreed to allow Ukraine to use Storm Shadow missiles on targets inside Russia. The green light came days after Joe Biden, the US president, agreed to do the same for the similar American long-range Atacms weapon.

The decision to approve the strikes was made in response to the deployment of more than 10,000 North Korean troops on Russia’s border with Ukraine, which UK and US officials warned was a significant escalation of the near three-year conflict.

Kyiv has since used Storm Shadow missiles to strike a command headquarters in the village of Maryno in the Kursk region. On Wednesday, Bloomberg reported that Britain had sent dozens more of the missiles to Ukraine several weeks ago.

Last week, the Russian president, Vladimir Putin, intensified the already fraught standoff with the west by launching an experimental ballistic missile at a military target in the Ukrainian city of Dnipro. He also said that Moscow “had the right” to strike western countries that provided Kyiv with weapons used against Russian targets.

Since Russia’s full-scale invasion of Ukraine, the UK and Russia have periodically engaged in tit-for-tat expulsions of diplomats, reflecting strained relations. In May, Britain expelled a senior Russian defence attache, accusing them of operating as an undeclared military intelligence officer. In retaliation, Moscow ordered the British defence attache to leave Russia.