The UK government has delayed for six months its decision over consent for the world’s largest planned offshore wind project – Orsted’s 2.4GW Hornsea 3 – after bird charities raised last minute fears over its impact.

UK energy secretary Andrea Leadsom was due to give a decision on 2 October on whether to approve the huge development off eastern England.

But that has now been pushed back to 31 March 2020 after UK planning officials received late advice from bird charity RSPB and Natural England, which claimed the wind farm, in conjunction with others in the area, would threaten gannet and kittiwake populations in the North Sea.

Orsted has been asked to comment on the new submissions, and offer suggestions to mitigate any impact, by the end of the year.

Hornsea 3 is the largest of the trio of giant wind farms Orsted is constructing the area. Hornsea 1 is already nearing full power as the world’s largest operating offshore wind farm at 1.2GW, and the 1.4GW Hornsea 2 is due online in 2022.

Lengthy legal action by the RSPB in Scotland caused several years of delays to projects there, and bird conservationists in Germany have also turned up the legal heat on offshore wind developers.

Orsted itself was recently told to think again over plans to double the size of its 573MW Race Bank offshore wind farm after seabed landlord The Crown Estate said it could not rule out adverse environmental impacts.

Orsted said in a statement sent to Recharge: "We are currently reviewing the notice from the secretary of state and will work closely with the relevant stakeholders to provide a response in due course. We continue to work towards a positive decision on Hornsea Three in March 2020."

The UK last week awarded power deals to a clutch of huge new offshore wind farms that would create a 5GW cluster of projects in the Dogger Bank zone further north.