TV watchdog Ofcom has launched a further 12 investigations into RT and said it is considering whether the news channel should retain its licence.

This brings the total number of probes into the “due impartiality” of programmes on the Russian state-controlled network to 27.

Boris Johnson has criticised RT and called for an Ofcom review, while Culture Secretary Nadine Dorries has also told the watchdog to review its operations.

A statement released by the regulator on Wednesday said: “Ofcom has today opened a further 12 investigations into the due impartiality of programmes on the RT news channel.

“This takes the total number of RT programmes under investigation to 27.

“We are very concerned by the volume of programmes on RT that are raising potential issues under the Broadcasting Code, and as we progress our investigations we are considering whether RT should retain a UK licence.”

Ofcom chief executive Dame Melanie Dawes previously said the body would be concluding its investigations “as a matter of urgency” given the “serious ongoing situation in Ukraine”.

The network – formerly Russia Today – was unavailable on Sky, Freesat and Freeview on Wednesday.

It comes after European Commission president Ursula von der Leyen announced over the weekend the channel would be banned in the EU.

Concerns have also been raised about RT by Labour leader Sir Keir Starmer, who labelled it Russian President Vladimir Putin’s “personal propaganda tool” which spreads “lies and disinformation”.

Ms Dorries has described the channel, which broadcasts internationally in languages including English, French and German, as “demonstrably part of Russia’s global disinformation campaign”.

However, Foreign Secretary Liz Truss has warned the BBC risks being banned in Russia if the Kremlin-backed broadcaster is shut down in the UK.