A north London police chief has called on the Jewish community to provide evidence that a planned extremist rally in Golders Green will be antisemitic so he can stop it.

Barnet borough commander Adrian Usher said that if it could be proved that the rally was “motivated by antisemitism, then that is clearly against the law and we will take robust action.”

He was responding to calls from the community that the rally, promoted by far-right group New Dawn as an attack on “Jewish privilege”, should be banned. It is due to take place on July 4, a Shabbat .

As the demonstration will be static, it cannot be banned unless it is proven to be antisemitic. It is understood that a radical move to prohibit all protests in the borough for a month would be a last resort. The measure has only been used once before, ahead of the funeral of fusilier Lee Rigby.

Jewish grassroots group the Campaign Against Antisemitism is proposing to hold its own counter-protest, and has attracted support from over 1,400 people.

Using the slogan “They Shall not Pass” — an echo of the Jewish struggle against anti-fascists at the Battle of Cable Street in 1936 — CAA has urged the community to “stand united” against a “neo-Nazi demonstration”.

Chief Superintendent Usher urged Jews not to overreact. He said: “I need the community to be calm and consider their response on hard facts. I appreciate it’s a highly emotive issue, but the law does not consider emotion, merely fact.”

A CAA spokeman said: “It is outrageous that in 2015, neo-Nazis are being allowed to hold a demonstration in Golders Green on a Saturday when their sole purpose is to intimidate and incite.

“We were promised zero tolerance but just weeks after the election, neo-Nazis are planning a bare-faced racist rally under police protection. We have been working hard to get the police to impose section 14 of the Public Order Act but so far our request has been ignored”.

The Board of Deputies and the Community Security Trust have backed the CAA protest. Newly elected Board president Jonathan Arkush said: “It is explicitly antisemitic to talk about Jewish privilege and as such it is totally unacceptable and it must be and it will be resisted to the finish by our community.

“I don’t think we can or should ignore it even if it is a pathetic collection of old men from another discredited age. The Jewish community must show its united determination, and not only the Jewish community, but all elements of society, should show their utter contempt for these people.

“So that means that we absolutely will need to demonstrate physically our total opposition and repugnance.”

Mark Gardner, CST’s director of communications, said: “Counter-protests may raise controversy, but the moral and political need to oppose neo-Nazis in Jewish areas is clear.

“This is an opportunity for Jews and non-Jews to stand firmly against antisemitism, whether by counter-protest or any other means.”

An example of “Jewish privilege", according to the New Dawn website, is the neighbourhood watch group Shomrim, which is described as the community's "own Police force”.

Shomrim chief executive Gary Ost said: “We are not a police force. We work very closely with the Metropolitan Police to assist with reducing criminal activity in our operational areas.

“Shomrim is being used as an excuse for those who may wish to incite racial hatred and their antisemitic views.”