The new Equality Act, which comes into force next month, could expose Jewish charities to a higher risk of discrimination claims, the Jewish Leadership Council has warned.
A paper circulated by the JLC says that the new act could have "unexpected consequences" on community life.
Last year courts applied race relations law in order to prevent Jewish schools from choosing pupils on the basis of their parentage. The use of an established law to challenge Jewish school admissions had been unforeseen by communal authorities.
Jeremy Newmark, JLC chief executive, said this week: "We are concerned that some of the provisions in the Equality Act could lead to surprising and damaging legal challenges against Jewish institutions in the future."
All charities that serve the Jewish community, he said, "will have to spend time and money reviewing their operations again. These new rules impose yet more restrictions and regulations on struggling Jewish charities".
Under the act, charities will still be able to restrict their services to members of a particular religion or ethnic group. But the JLC believes that the wording of the act could make it harder for charities to justify their policy in some circumstances.
Jon Benjamin, chief executive of the Board of Deputies, said that the Board had been consulting with the Equalities and Human Rights Commission in order to minimise any legal threat to Jewish institutions.
He added: "We will keep working with other faith groups and community partners to ensure that there are no unintended consequences."