Under pressure from parliamentarians, Britain's Culture Secretary Nadine Dorries has ordered the media regulator to review Russia Today (RT) broadcast content.
Earlier, Labor Party leader Keir Starmer had criticized the Kremlin-funded Russian channel's English-language channel as President Putin's "personal propaganda tool".
In connection with his criticism of the Johnson administration's scant sanctions against Russia, Starmer called for a ban on RT.
Prime Minister Boris Johnson replied that in a democracy that believes in the right to free speech, it should be for media regulator Ofcom, not politicians, to decide.
Nadine Dorries wrote to Ofcom's chief executive that RT has been shown to be involved in the Kremlin's global disinformation campaign.
The minister called for early and transparent measures to limit Russia's ability to spread propaganda.
The regulator said it was keeping a close eye on reporting on Ukraine.
RT didn't mention them, though.
Some MPs have expressed concerns about the Russian channel being banned over fears of Russian retaliation.
The BBC already deals extensively with Putin's propaganda for millions of people.
Scottish First Minister Nicola Sturgeon expressed her "dismay" that her predecessor Alec Salmond is staying on at RT.
Salmond has hosted his own talk show on the network since 2017.
Three years ago, Ofcom fined RT £200,000 for repeated breaches of objectivity rules in connection with the Russian poisoning attack in Salisbury and the war in Syria.