Police and prosecutors have been accused of betraying British Jews by failing to crack down on anti-Semitic crime.
New research suggests suspected hate offences targeting Jewish victims surged for the third consecutive year in 2016, reaching the worst level on record.
But at the same time the number of charges fell "drastically" - with alleged perpetrators charged in fewer than a tenth of cases, campaigners say.
They also claim a "paltry" 15 cases were prosecuted last year.
The Crown Prosecution Service (CPS) said it does not recognise this figure.
Anti-Semitic crimes recorded by police forces around the UK increased by 14.9% in 2016, according to figures provided following Freedom of Information requests.
The total of 1,078 offences registered last year compared to 938 in 2015 and 746 in 2014.
Gideon Falter, chairman of the Campaign Against Antisemitism, which compiled the analysis, said: "The failure of police forces and the Crown Prosecution Service to protect British Jews is a betrayal.
"The solutions are simple, but whilst the right promises are being made, little has been implemented.
"The result is that British Jews continue to endure intolerable levels of hate crime.
"Britain has the political will to fight anti-Semitism and strong laws with which to do it, but those responsible for tackling the rapidly growing racist targeting of British Jews are failing to enforce the law.
"There is a very real danger of Jewish citizens emigrating, as has happened elsewhere in Europe unless there is radical change."
The campaign's report warned that a consistently elevated level of anti-Semitic crime has become the "new normality" for British Jews since the middle of 2014.
Forces recorded 105 violent offences against Jews in 2016 - which was down by 44% on the previous year, the assessment found.
It said 2016 saw the number of anti-Semitic crimes charged fall by 30.5%, with 89 resulting in charges being brought - or 8.3% of the total number of offences recorded.
The campaign said it had ascertained through a review of its own and other charities' data, as well as press reports, that 15 alleged anti-Semitic crimes were prosecuted in 2016.
The CPS said it is wrong to claim it does not take prosecuting anti-Semitic crime seriously.
A spokesman for the service said: "Last year we prosecuted more hate crimes than ever before - more than 15,000 cases.
"We do not recognise the statistics contained in this report.
"Religiously-aggravated hate crimes display an ugly element of society which can be devastating to victims who have been targeted because of their beliefs.
"We will always prosecute crimes against people of all faiths where there is sufficient evidence and it is in the public interest to do so."
The report recommends training and guidance on anti-Semitic hate crime for officers and prosecutors and called for police forces' responses to the offences to be examined by watchdogs.
Home Secretary Amber Rudd said: "Everyone in this country has the right to be safe from violence and persecution.
"We are working together to tackle anti-Semitic hate crime in all its forms and using the full force of the law to protect every person in the UK."
National policing lead for the issue Assistant Chief Constable Garry Shewan said: "Nobody should have to face violence because of who they are.
"The police service is committed to tackling all forms of intolerance and hate-motivated crime, but to do so we need all victims or witnesses to come forward and report these incidents to us.
"I want to reassure all communities that you will be listened to, taken seriously, and officers will do all they can to bring offenders to justice."