Labour's John McDonnell has said he will no longer appear on Russia's state media network.
Speaking on the BBC's Andrew Marr show, the shadow chancellor said Russia Today's coverage "goes beyond objective journalism", and that he will be encouraging colleagues to turn down offers to appear on the channel.
The decision comes after Russian spy Sergei Skripal and his daughter Yulia were poisoned in Salisbury.
McDonnell said that he had previously felt it was right to appear on Russia Today to be fair to media organisations from other countries, but that the network's coverage had changed.
However, McDonnell's deputy Peter Dowd appeared on Russia Today only yesterday.
Chancellor Philip Hammond said the Conservative party would continue to take donations from Russians.
"I don't think we should be tarring them with Putin's brush," he said.