The UK is accusing Russia’s Security Service, the FSB, of a sustained cyber-hacking campaign, targeting politicians and others in public life.

The government said one group stole data through cyber-attacks, which was later made public, including material linked to the 2019 election.

Russia has repeatedly denied claims it is involved in such activities.

Foreign Secretary David Cameron said the group’s actions were “completely unacceptable”.

“Despite their repeated efforts, they have failed. We will continue to work together with our allies to expose Russian covert cyber activity and hold Russia to account for its actions,” the former prime minister said.

Foreign Office Minister Leo Docherty told the House of Commons on Thursday that Russia’s ambassador has been summoned and two individuals were being sanctioned. One of them is a serving FSB officer.

The Russian ambassador was unavailable after being summoned on Wednesday, but officials instead met with the Russian Embassy’s deputy head of mission and expressed the UK’s deep concern about the alleged cyber-attacks.