Britain’s biggest waste project – and one of the biggest current private finance initiative deals – was finally signed off on Wednesday amid tentative signs that banks may be rediscovering their appetite for PFI projects.

However, the deal, which is critical to the government avoiding European Union fines for sending too much waste to landfill, was finally closed only after almost £350m of taxpayer’s money was injected into the project, which has a capital value of £640m.