British Jewish groups have condemned the move by Israeli Prime Minister to forge an alliance with extremists linked to the banned Kahanist movement.

Benjamin Netanyahu is seeking to unite the fringes of Israel's right wing ahead of the election in April.

His Likud party will reserve the 28th spot on its own list for Habayit Hayehudi, a pro-settler party, on condition that it forms a separate joint list with the extremist Jewish Power faction.

The hard-line members of Jewish Power advocate the forced removal of Palestinians and turning Israel into a Jewish theocracy.

They also describe themselves as the successors to the banned Kahanist movement, named after the late Rabbi Meir Kahane, whose Jewish Defence League was labelled a terrorist organisation by the United States.

Responding to the news Adam Ognall, CEO of the New Israel Fund, said the move signified a “horrifying” development in Israeli politics.

Mr Ognall said: "Meir Kahane was a violent supremacist who advocated and inspired acts of terror. He and his disciples were rightly banned from the Knesset in 1988 on the grounds that their ideology is 'racist and undemocratic.'”

He argued that people from across the political spectrum in Israel have “largely agreed that Kahanists are a danger to Israeli democracy and have no place in its Parliament.

“It is both horrifying and very revealing that Kahanists are now returning to the political arena and are being courted and embraced by right-wing parties and their leadership.”

He said NIF would “stand with all Israelis and against those who use violence, terror, and supremacist ideologies to divide and rule by fear.

“Elected leaders have a sacred responsibility to protect Israelis from violent extremists-- not promote them."

Yachad's Hannah Weisfeld said the leaders of the newly merged faction “represent values that are inimical to anyone that considers themselves to be a believer in democracy, justice and Jewish values.”

Ms Weisfeld said that all friends of Israel whether that is the British government, or establishment Jewish community organisations “must speak up against this messianic, racist, terror-supporting group who falsely claims its dangerous ideology stems from Jewish tradition”.

When asked to comment, the Jewish Leadership Council and the Board of Deputies said it was not their normal policy to comment on Israeli elections.

Ms Weisfeld said those groups who do not condemn the move run the risk of “conflating support for Israel with support for outright racism, homophobia and anti-democratic beliefs.”

Zionist Federation chairman, Paul Charney, said that while “stormy political manoeuvring” in Israel prior to the elections is expected, Mr Netanyahu must know “that joining with the wrong or unpopular bed-mate might ultimately be the cause his downfall.”

Mr Charney said: “These alliances tend not to last. PM Netanyahu has more experience than most, but, he must also know that joining with the wrong or unpopular bed-mate might ultimately be the cause his downfall. 

“We at the ZF have full faith that the Israeli public will make the right and proper choice on election day.  Anything else and Israel will be heading straight back to elections.”