A former Labour member who was expelled by the party has been charged with an offence under the Communications Act as part of a police investigation into alleged antisemitism.
Mohson Rasool, 60, is charged with sending "a grossly offensive message or other matter" on February 10, 2018.
But on Wednesday the Metropolitan Police said that four other individuals, three men and a woman, had been told they will face no further action as part of an investigation was prompted by an internal Labour dossier detailing antisemitic messages on social media allegedly posted by party members.
Mr Rasool's case was one of five that were originally handed to prosecutors between March and July 2019 after Met Police Commissioner Cressida Dick was handed a dossier of allegations by LBC Radio.
He is accused of sending a message on a "public electronic communications network" on 10 February 2018 that was "grossly offensive", contrary to Section 127(1) of the Act and was arrested on 7 March 2019. He was expelled by the party before he was arrested.
A sixth case involving a man in his 60s from Bradford, who was interviewed under caution on suspicion of distributing material likely to stir up racial hatred, is still being looked at by police.
In a statement the CPS said: "Antisemitic hate speech is unacceptable and when our legal test is met, we always seek to prosecute.
“The laws designed to tackle hate speech on social media set a high standard and there is a distinction between what is merely offensive or hurtful and what constitutes a criminal offence.
“Some of the messages were posted too long ago for a prosecution to be possible.
“In other instances it could not be established if the suspects had intended to stir up racial hatred or there was likelihood of such hatred being stirred up.”
Following the decision, the Campaign Against Antisemitism said it would consider bringing a private prosecution against the four activists who are facing no further action, and applying for a judicial review of the case.
Chief executive Gideon Falter said: “When the CPS has failed to prosecute in the past we have successfully instigated private prosecutions and brought judicial review proceedings against the CPS.
“We had hoped that these measures would not be necessary every time antisemitic hate crimes come before the CPS, but yet again we find ourselves having to consider our options with our lawyers in order to deliver justice for the Jewish community, because the CPS has failed us.”
Five further cases - on top of the six - were passed to prosecutors on February 10 for "early investigative advice", the Metropolitan Police said.
None of the five new individuals involved have been arrested, interviewed under caution or named.
The Labour Party previously welcomed the police investigation and said: “Antisemitism has no place in our society and we are committed to challenging and campaigning against it in all its forms.”
