One of the most hotly debated privatisations of recent years has attracted fresh controversy after the Green Investment Bank’s trustees said they were “disappointed” by its weak investment in the UK since it left state hands.

The clean power lender was sold to the Australian bank Macquarie in 2017 for £2.3bn and renamed the Green Investment Group (GIG), which widened its investment remit beyond the UK.

The hasty privatisation of the lender, which had been set up only five years earlier to pump cash into renewable energy projects, caused a backlash at the time with critics warning that Macquarie would strip its assets. Ministers insisted on the creation of a board of trustees to ensure it stuck to its green mission, and to assuage concerns