United Synagogue president Stephen Pack considered warning members of the Board of Deputies to vote against the admission of the campaign group Yachad, over its "unacceptable activities", it has been revealed.

In an email seen by the JC, Mr Pack said he had been pressed to write to representatives of US congregations on the Board to oppose Yachad's application.

But he told the JC on Wednesday that the US was not going to recommend a position ahead of the vote at the Board's meeting on Sunday. "I believe there has been enough publicity about all the issues, so people will make their own decision based on the facts," he said.

The Board has twice postponed a vote on whether to accept Yachad, which advocates a two-state solution and runs fact-finding missions to the West Bank.

Mr Pack said that he remained concerned about the group because some Yachad representatives have "indicated support" for sanctions against Israel, although he recognised that this was not the group's official policy.

Mr Pack last week emailed George White, co-ordinator of the United Synagogue Deputies' Advisory Group, saying that members wanted him to write to US deputies "telling them that the US is not in favour of Yachad joining the BoD in view of their support for sanctions and other measure[s] which many perceive as anti-Zionist."

Mr Pack said he was not sure the US could do this, adding that it had to be "extremely careful" about making political statements. But he wondered whether the advisory group itself should write to US deputies about Yachad's "unacceptable activities".

US members occupy a large bloc on the Board but deputies are free to cast their vote as individuals. Yachad needs a two-thirds majority to gain a seat.

Mr White said that, following consultations with a small sample of US deputies, it had been agreed not to send out an advance briefing. "Based on the Board's constitution, US deputies are free to vote how they wish," he said.

Explaining his concern about Yachad, Mr Pack cited a blog on the Times of Israel written by Barry Shaw, a British oleh who has campaigned vociferously against its membership of the Board.

Mr Shaw wrote that in 2012, Yachad's director Hannah Weisfeld had taken part in a discussion with supporters of the Boycott, Divestment and Sanctions movement and stated "I didn't tell anyone here not to support BDS".

But Ms Weisfeld said this week: "Yachad does not and has never supported sanctions."

She added: "It's a shame that a completely out of context quote, in an article written by someone who has an agenda to stop Yachad from entering the Board of Deputies, is being used as a basis to form opinions of the organisation and its representatives."