The Labour candidate for Coventry South has come under renewed pressure after the JC discovered another social media message appearing to contravene IHRA guidelines on antisemitism.
Zarah Sultana taunted the departing vice president of the National Union of Students by claiming he did not "serve Israel as well as you would've liked."
The 26 year-old, a West Midlands Labour staffer, also suggested ex-NUS official Joe Vinson should move to Israel after he spoke out about antisemitism and support for the BDS campaign within the student movement.
Evidence of the new Twitter message, which appeared to contravene the IHRA definition of antisemitism, emerged only days after Ms Sultana said she had "been on a journey" to help her avoid straying into comment that was racist.
She said she had been "working closely with Jewish comrades who have taught me about the language and history of antisemitism” and cited a trip to Auschwitz in 2013 as helping with this leaning process.
One tweeter wryly noted that her journey "appears to have been a round trip".
In the latest controversial message Ms Sultana attacked Mr Vinson after he blocked her on Twitter in 2015.
She wrote: "Under your 'leadership' you lost control of NUS....and you didn't serve Israel as well as you would've liked."
Ms Sultana then wrote to Mr Vinson, who grew up in Cornwall, that "you can always got to Israel and work on anti-BDS campaigns as you did so well in the UK."
During his days in the NUS Mr Vinson, who is not Jewish himself, was said to be an "amazing ally" of those opposing the drift into hard-line anti-Israel sentiment within the student movement.
In June 2015, he had tweeted: "Antisemitism is like a virus, it mutates and infects everything it touches. It's mutated into BDS and NUS is infected."
Ms Sultana has already apologised for saying it was ok to “celebrate the death of any person regardless of what they did” after the JC published her social media remarks earlier this month.
The former Birmingham University student was revealed to have written: “Try and stop me when the likes of Blair, Netanyahu and Bush die.”
Ms Sultana, who sat on the national executive of Young Labour and the national executive council of the National Union of Students, also wrote of her support for “violent resistance” by Palestinians.
The JC has contacted Labour for comment.