In the first, conducted by the pollster YouGov for the Campaign Against Anti-Semitism (CAA), a lobby group, 45 percent of all respondents agreed with at least one anti-Semitic view that was presented to them. One in four said that Jews "chase money" more than others, while one in six agreed that "Jews think they are better than other people" and that Jews "have too much power in the media."

The second survey, also released by the CAA looked at Jewish attitudes. The survey was carried out on social media, and found that more than half of respondents feared that Jews have no future in the UK.

"We carried out these surveys because of anecdotal evidence that people were concerned," says Jonathan Sacerdoti, spokesman for the CAA. "Whilst Jews in Britain are safer than in parts of Europe, they are aware of incidents happening in France, Belgium, and elsewhere, and of similar plots here."

Recent events in Paris, when terrorists took people hostage at a kosher supermarket, killing four, have ramped up anxiety. "I haven't personally experienced anti-Semitism, but I feel more and more aware of this sentiment growing," says Daniel Cohen, from London. "Looking at events in Europe is obviously worrying. With the rise of radical Islam, it feels like something similar could easily happen here in the UK."

Worrying trend

The increase in anti-Semitism noted by researchers predates the Paris attack. The Community and Services Trust (CST) keeps records of hate crimes against Jews, and reported a 36 percent increase in the first six months of 2014. Particular spikes have been seen after increased tensions in Israel. After the bombardment of Gaza in July 2014, over 100 hate crimes against Jews were reported in the UK; well above the average.

"The CAA survey of the Jewish community reflects the high levels of anxiety and concern in the Jewish community about anti-Semitism," says Dave Rich, spokesman for the CST. "This anxiety is real but it is important to remember that the current level, and nature, of anti-Semitism in Britain is not as bad as we have seen in France and other European countries. We are working closely with the police and government to ensure that British Jews can continue to go about their lives with pride and confidence."

Ask around on the streets of London and it becomes clear that people are not necessarily surprised but increasingly worried about the sharp spike in anti-Semitic sentiment and prejudice. "It doesn't surprise me at all that people believe these things about Jews," says Anna Solemani, who lives in London. "Lots of people have this vague sense that things are run by Jews. It worries me that anti-Semitism is becoming something people are tired of, that they don't see it as an issue any more, and portray it as something that is just thrown around by Jews to stop people criticizing Israel, rather than real prejudice that needs to be fought. That is frightening."

Using Israel as a pretext

CAA spokesman Sacerdoti notes that the debate around Israel can often be a cover for anti-Semitic views. "It is not true at all that all debate about Israel is anti-Semitic - but some people find they can engage in anti-Semitic behaviour and language when there's an increase in that debate and get away with it," he says.

Previous studies have found significantly lower proportions of anti-Semitic sentiment than the YouGov/CAA poll. The 2014 Pew Global Attitudes survey found that less than 10 percent of the British public held a negative view toward British Jews. A survey by the Anti-Defamation League found a similar proportion, at 8 percent. "These figures are probably more accurate," says Dr Jonathan Boyd, executive director of the Institute of Jewish Policy Research (JPR). "At the same time, I would say that people are rattled by what's happened in France and are monitoring things more carefully."

Not about to leave

Some have questioned the CAA's second survey on Jewish attitudes, in which a significant proportion of respondents said they did not see a future in Britain. Spokesman Sacerdoti notes that the poll is just a snapshot that doesn't necessarily reflect the position of the entire Jewish community - a sentiment backed up by Jewish residents in London. "I definitely wouldn't say I'm planning on leaving the UK any time soon," says Cohen.

Last year, the JPR published a report on British Jews and anti-Semitism, and found by contrast that 47 percent did not feel it was a major problem (although 40 percent felt that it had increased in the last five years). "The CAA survey is methodologically very problematic," says Boyd. "I don't think Jews are packing their suitcases and fleeing the country at all."

While there may be debate about the exact numbers, most agree that British Jews are increasingly concerned about anti-Semitism, and that the issue should be high on the agenda. Campaigners can take hope from the government's strong response to the YouGov poll. "Anyone who peddles anti-Semitic views is attacking Britain and British values," said Eric Pickles, the communities' secretary. Sacerdoti says that Britain is at a "tipping point" and that the situation could be improved with firm action from the authorities and from civil society.

The CST's Rich agrees. "These studies show that a stubborn minority of people in Britain cling onto outdated anti-Semitic stereotypes. It is important for everyone to work together to eradicate these attitudes as part of building a tolerant, diverse yet cohesive society."