Chancellor of the Exchequer George Osborne has authorised the creation of a Green Investment Bank by 2013 and pledged £3bn to fund its growth, but he refused to give it the power to borrow money until 2015 at the earliest.

The measure falls short of urgent borrowing powers proposed last year by a commission led by former investment banker Bob Wigley, the ex-chairman of Merrill Lynch in Europe. Osborne said the issuance of green bonds would have to wait until debt as a percentage of GDP has fallen.