Conservationists battling the Hampstead Heath ponds project have sent a warning shot to the City of London Corporation over a proposed legal challenge.

Lawyers acting for the Heath and Hampstead Society today sent a legal letter to the Corporation outlining the society’s case that the proposed dam works are unlawful.

The “letter before action” is the first step towards a judicial review of the City’s plans.

The society, which is leading the Dam Nonsense campaign against the works, says it has three main legal grounds for challenging the decision.

They are:

– That the City’s decision is based on an erroneous interpretation of the words “in the interests of safety” in the Reservoirs Act 1975.

– That it is based on an irrational and/or unlawful approach to risk.

– That the decision is the result of a process which should have been, but was not, subject to a “strategic environmental assessment” in accordance with European law.

Marc Hutchinson, chairman of the Heath and Hampstead Society, said: “The society has challenged the City to rescind its decision, and to take any further decisions regarding the works at the ponds on the correct legal basis.”