The chair of the historic Bevis Marks synagogue in the City of London has warned of the “catastrophic” impact of a proposed 48-storey tower block which would be constructed 25 metres away.

In a letter to members of the Grade I-listed shul – the only European synagogue to have held regular services for more than 300 years - Jonathan Solomons wrote that the planned development in Bury Street would result in Bevis Marks losing “much of our light, both to the courtyard and inside which will impact on our ability to pray”. He urged members to register objections with the local authority.

The Bury Street proposal from the West End of London Property Unit Trust (Welput) would provide more than 3,000 square metres of office space. It is the second large project the synagogue is trying to block, supporters having contributed to the 1,000-plus objections to a development in Creechurch Lane, which is currently under council consideration.

Mr Solomons cited the “unique history” of Bevis Marks, likening it to nearby St Paul’s Cathedral. “One cannot begin to imagine this kind of encroachment being permitted on the doorstep of St Paul's, despite Bevis's similar importance to people of the Jewish faith,” he wrote.

The shul’s rabbi, Shalom Morris, described the proposals as “unsympathetic [and] inappropriate”. If both the Bury Street and Creechurch Lane projects were green-lighted, they would collectively be “profoundly detrimental to the heritage and to the functioning of the synagogue”. The Bury Street proposal would result in the synagogue suffering a more than ten per cent reduction in daylight.

In normal circumstances, the synagogue would have hundreds of visitors a week, as well as three-figure attendances at services. He anticipated that any construction work would impact on the experience as it would involve a significant level of noise.

Rabbi Morris added that the fight was “challenging” for a small charity facing developers with “very deep pockets”.

Alexander Morris, development director for Welput owner BentallGreenOak, told the JC that he had been in “regular dialogue” with the synagogue. The proposed Bury Street building would sit within the Eastern Cluster, a “designated zone for taller buildings” which includes St Mary’s Axe and 100 Leadenhall.

He noted that the synagogue “is sitting, unfortunately, within a zone that well before I was involved with [the proposal] has had many developments".

Mr Morris maintained that the reduction in daylight the Welput building would have on the synagogue’s courtyard would amount to only one per cent.