Three judges overturned an earlier High Court ruling giving the green light for the cull to go ahead.
BAE Systems wanted to cull more than 1,000 birds at the Ribble Estuary on the Lancashire coast, at a site only two miles west of BAE’s Warton Aerodrome. However, the Royal Society for the Protection of Birds (RSPB) challenged the plans at a hearing earlier this month.
The original approval for the cull of lesser black-backed gulls was given by then Secretary of State for Rural Affairs, Owen Paterson.
However at the Appeal Court Lords Justices Jackson, Sullivan and Sales turned the RSPB’s earlier defeat into victory and ruled the Secretary of State’s decision was “flawed” and quashed the order granting the cull.
The RSPB had argued lesser black-backed gulls are a species “under significant pressure” in the UK and the level of the cull was too high.
In their decision the judge’s said the Secretary of State in giving the go-ahead for the cull had “misinterpreted the conservation objectives,” and added he had “wrongly used a generic threshold which allows for natural fluctuation in bird populations” to set the level of the cull.
The colonies are on a Site of Special Scientific Interest between Southport and Lytham and St Annes which forms part of the Ribble and Alternative Estuaries Special Protection Area on the coast of Merseyside and Lancashire.
In the decision under challenge, taken last May, the Secretary of State had directed Natural England to give BAE Systems consent to cull the birds and keep the population to no lower than 3,348 pairs.