Israel is attempting to smear activists who question the illegal occupation of Palestinian land by helping to build racism cases against them, an investigation by Al Jazeera's Investigative Unit reveals.

The investigation, The Lobby , also uncovers Israel's extensive, well-financed propaganda campaign in the UK to counter negative news stories about its policies and to fund trips to Israel for young activists.

As part of a six-month investigation, Robin, an undercover reporter using an alias, infiltrated a lobby of politicians, activists and Israeli embassy officials working to drum up support for Israel.

Many enjoyed financial or strategic support from the Israeli embassy in London via Shai Masot, a senior policial officer at the embassy.

During the investigation, Michael Rubin, a young Labour and pro-Israel activist, told Robin that he worked "with the ambassador and embassy quite a lot".

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"We work really closely together," he said, "but a lot of it is behind the scenes."

"The embassy helps us quite a lot," he said. "When bad news stories come out of Israel, the embassy sends us information so we can counter it."

Party conference

Robin posed as a graduate activist with strong sympathies towards Israel who was eager to launch a pro-Israel youth group within the opposition Labour Party and help combat the Boycott, Divestment and Sanctions (BDS) movement.

In September, Masot took Robin to the 2016 Labour Party conference in Liverpool. On the sidelines, Mike Katz, vice chairman of the Jewish Labour Movement, held a training session regarding anti-Semitism, which Al Jazeera filmed secretly.

Some Labour members raised questions over the definition of anti-Semitism, and were soon accused of racism.

When the discussion moved to the subject of Zionism, the political ideology that Israel has the right to exist as an exclusively Jewish homeland in historic Palestine, some attempted to debate the issue.

"Anti-Semitism, like any form of racism is deplorable and my feeling about how to tackle this is for Jews to be standing firmly and squarely alongside our black comrades, our Muslim comrades, who are much more at the moment the target of racism than thankfully we are," said leading Labour activist Jackie Walker, a black British Jew.

She added that she hadn't "heard a definition of anti-Semitism [within the session] that I can work with", and concluded: "If you are saying effectively that Zionism is not open to debate as a concept, then that is really worrying."

Walker soon faced threats and criticism.

Footage (not Al Jazeera's) of her comments appeared on the internet and news of the event hit British newspaper headlines the next day. She was later suspended from the Labour Party pending an investigation and lost her role as vice-chairwoman of Momentum, a left-wing organisation supportive of Labour leader Corbyn.

When Robin asked Masot about Walker, the Israeli diplomat said: "She is problematic."

"Do not let it go," he advised, and urged Robin to report "all of the party" members who make similar comments.

'I could take her'

Later, Ella Rose, director of the Jewish Labour Movement who previously worked at the Israeli embassy, discredited Walker, calling her a "f******g anti-Semite".

She boasted of having undergone training in Krav Maga, a hand-to-hand combat technique developed by the Israeli military.

"You know what, I could take her. She's like 5ft 2in and tiny," Rose told Robin.

Al Jazeera showed Walker the footage of Rose. She said: "If they accuse anybody of anti-Semitism it is basically as bad as kind of accusing somebody of being a paedophile or a murderer."

Walker added that for her, it was "really hard to come back from that" accusation.

Yossi Melman, an Israeli journalist and writer who specialises in security and intelligence affairs told Al Jazeera that in recent years, there is a growing tendency within the government to smear people who are anti-Israeli, or anti-Zionist, also to be anti-Semite.

"But not all anti-Israelis and anti-Zionists are anti-Semites, on the contrary".

Israeli historian Ilan Pappe added: "In the past, anti-Semitism was hating Jews for being Jews.

"Now Israel tries to extend it to say that any criticism about what Jews are doing is also anti-Semitism.

"If you question the right of Israel to be a Jewish state, then you are not different from these classical anti-Semites."

Mystery million

During the Labour Party conference, Robin recorded a discussion between Masot and Joan Ryan, a Labour MP and head of Labour Friends of Israel, at an LFI stand in which they alluded to a fund of more than £1m from the Israeli embassy used to send activists and politicians on paid trips to Israel.

Ryan said that she selected the candidates for the trip. "What happened with the names that we put into the embassy?" she asked Masot.

"Just now we've got the money, it's more than £1m, it's a lot of money," he replied. "it's not physical, it's an approval."

"I didn't think you had it in your bag!" joked Ryan.

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The LFI told Al Jazeera that the conversation between Masot and Ryan had nothing whatsoever to do with LFI delegations.

The LFI added that no payment of £1m was offered, given or received by them and the names of individuals supplied by Ryan were for a visit arranged, advertised by and paid for by the Israeli embassy.

The group said Masot was claiming influence he did not have and that any young LFI grouping would be organised by the LFI and not the embassy.

By the time of publication, no one had clarified to Al Jazeera to whom the £1m was to be paid.

Melman described foreign delegations to Israel as an important part of a "propaganda campaign".

"The government of Israel has already a budget allocated to various ministries which can use it as they like, to bring foreign delegations to Israel," he said. "It's part of the information campaign, you may call it a propaganda campaign."

The LFI said that they work alongside many organisations - both Israeli and Palestinian - as well as the Israeli embassy.

Al Jazeera Investigative Unit's series "The Lobby" can be viewed on Al Jazeera:

Episode One: Young Friends of Israel – Available online

Episode Two: The Training Session - Thursday, January 12, 22:30 GMT

Episode Three: The Anti-Semitic Trope - Friday, January 13, 22:30 GMT

Episode Four: The Takedown - Saturday, January 14, 22:30 GMT