A neo-Nazi website based in the US is behind a co-ordinated campaign of antisemitic abuse targeting Britain's youngest Jewish MP, the JC can reveal.
The site provides a user guide to harassing Luciana Berger and has created offensive images to be shared by internet trolls and sent to her via social media sites.
It carries a series of "dos and don'ts" for those who intend to abuse Ms Berger. The site advises trolls not to "call for violence, threaten the Jew b---h in any way. Seriously, don't do that".
But it goes on to encourage calling her "a Jew, call her a Jew communist, call her a terrorist, call her a filthy Jew b---h. Call her a hook-nosed y-- and a ratfaced k---.
"Tell her we do not want her in the UK, we do not want her or any other Jew anywhere in Europe. Tell her to go to Israel and call for her deportation to said Jew state."
Advice on the easiest ways to set up anonymous Twitter accounts and email addresses to limit traceability is also available on the website. It posts hundreds of racist articles targeting black people, Muslims and Jews.
Ms Berger received around 400 abusive messages on Twitter last week. Many carried the hashtags and images created by the American site, which urged trolls to join "Operation: Filthy Jew Bitch".
The campaign against the Liverpool Wavertree MP was set up last Monday, hours after Merseysider Garron Helm was jailed for sending her abusive messages.
Helm's imprisonment was heralded as an "important precedent", but it is now clear that his abuse was merely the tip of an iceberg.
The JC understands the Labour shadow cabinet member has received death threats amid the series of "deeply threatening" messages.
She has not commented on the abuse, but friends said she was feeling isolated after the "relentless" storm of offensive tweets.
"Luciana is sickened by what's flashing up on her phone on a minute-by-minute basis," said one. "It's hard for her being the focus of something so sinister and global and relentless."
A coalition of security groups, police and Twitter have been investigating the source of the messages and have shut down some accounts.
The operation against her is being orchestrated by the racist, white nationalist website Daily Stormer.
It is run by Andrew Anglin, who has previously been filmed at Berlin's Holocaust memorial mocking victims of the Shoah and questioning the number of Jews who were murdered.
The site promotes use of the #HitlerWasRight hashtag.
It provides what is effectively a resource pack of racist images which it advises trolls to use to "flood" Ms Berger's Twitter account. Among the images are those of the MP next to Labour's Jewish leader Ed Miliband with a yellow star with the word "Jude" superimposed on their heads.
The call to action concludes by urging abusers to use the hashtags #FilthyJewB---h and #FreeGarronHelm on every tweet targeting Ms Berger.
"We will not bow to Jews. We will not be silenced by Jews. We will not allow Jews to destroy the nations that our ancestors spilled blood on to build on this sacred land."
When Twitter began to block the tweets late last week, Daily Stormer users began posting Ms Berger's email address on internet forums.
A website claiming to be Britain's "number one nationalist newspaper" also highlighted Helm's conviction.
The Daily Bale, run by "nationalist" Joshua Bonehill-Paine, said that as a former director of Labour Friends of Israel, Ms Berger was a supporter of "institutional state child murderers", a "money grabber" and a war criminal.
The JC understands police are investigating the comments.
Ms Berger's parliamentary colleagues and members of the Jewish community have responded by posting messages of support online.
Lord Wood, a Labour peer and adviser to party leader Ed Miliband, wrote on Twitter: "The vile antisemitic abuse of Luciana Berger online only succeeds in uniting everyone in her support and in revulsion against those behind it."
Baroness Royall, Labour's leader in the Lords, tweeted: "Luciana Berger is a terrific MP, friend and colleague - a very fine woman. The racist abuse against her must stop. It's abhorrent."
Board of Deputies vice president Jonathan Arkush tweeted: "Racist abuse of Luciana Berger is nauseating and disfigures our country. Perpetrators should expect to go to prison. We value and support her."
The case was raised in Parliament on Wednesday, with Commons Speaker John Bercow condemning the abuse as "despicable and beneath contempt".