Iberdrola Renewables' decision threatens government target to generate 35% of country's electricity from renewables by 2020

Plans to build hundreds of new wind turbines across the UK suffered a major blow yesterday after the world's biggest investor in wind farms announced deep cuts to its spending programme.

Iberdrola Renewables said it would slash British investment by more than 40%, threatening government targets to generate 35% of the country's electricity from renewable sources by 2020.

The news comes in the same week the British Wind Energy Association wrote to the government highlighting a £2bn funding gap in the country's energy strategy and urging immediate action.

Nine schemes, including the £3bn London Array in the Thames estuary and Npower's £2.2bn Gwint y Mor farm off the Welsh coast, have planning permission but have not started construction. The BWEA said the recession had undermined firms' ability to finance major projects

Iberdrola's announcement will be a blow to energy secretary Ed Miliband, who earlier this week said opposing wind farms should become as socially unacceptable as not wearing a seatbelt.