The United Synagogue has hit out at the Federation of Synagogues’ new kosher meat operation, claiming that it could lead to price rises.

The Federation’s mehadrin meat range – aimed at strictly Orthodox consumers – went on sale in one London shop on Wednesday.

But in a sharply worded attack today, a US spokesman said that “contrary to the stated aims of this initiative, we fear that it will cause an increase in prices and jeopardise the security of UK shechita in the long-term”.

Both organisations, along with the Spanish and Portuguese Jews’ Congregation, jointly run the London Board for Shechita, which licenses kosher meat in the capital.

LBS president Benjamin Mire has already complained that the Federation venture was in “competition and conflict” with the LBS.

But the Federation has maintained that the new meat is intended to be an alternative to Kedassia, the kashrut arm of the Union of Orthodox Hebrew Congregations, and to attract customers not currently catered for by the LBS.

Its new mehadrin brand – which requires a stricter level of supervision than standard kosher meat – aims to provide a cheaper option to Kedassia.

But the US spokesman stated, “At a time when shechita itself is under attack, the United Synagogue, as part of the LBS, is committed to meeting the needs of kosher consumers to the highest standards of kashrut and quality at the best possible price. We fear that current developments will have precisely the opposite effect.”

The Federation said that it would respond to the US claims in due course.

Mr Mire last week wrote to the Federation to shock at hearing that the Federation had slaughtered beef in an Irish abattoir and given a licence to Gilberts, one of the LBS's main licensees, to supply it.

He feared that if Gilberts stopped buying from the LBS, that would lead to the closure of the Board’s cattle abattoirs in Manchester at risk, which could be “a catalyst for the demise of cattle shechita in the UK”.

But earlier in the week the Federation’s legal adviser, Professor David Rosen, explained that the organisation was responding “to a growing number of people who want to be additionally strict in line with the teachings and customs of their rabbonim, which is not currently catered for by the LBS. That does not diminish or detract from the standard or quality of the hechsher [kosher certificate] of the LBS".

The LBS rejected the Federation plan to launch the mehadrin range last month. Initially, the Federation had proposed splitting the proceeds from supervision of the new shechita three ways: among itself, the LBS and three rabbis supervising it. But earlier this year, a revised proposal from the Federation suggested the shechita fee to go to the LBS.

Professor Rosen said on Wednesday that the Federation still sought an “amicable solution”.