John McDonnell, the shadow chancellor, is calling on Philip Hammond to hold an urgent public inquiry into whether Bank of England officials colluded in the rigging of the Libor rate. The senior Labor politician said Hammond’s silence on the issue was unacceptable after a BBC Panorama program said it had evidence of pressure exerted by Threadneedle Street on the setting of Libor – the London interbank offered rate, which is the interest rate banks charge each other for short-term loans. Libor is used as a reference point around the world for loans and mortgages. Revelations that the rate was rigged at the height of the financial crisis led to banks being fined hundreds of millions of pounds from a variety of regulators, while bankers from Barclays and UBS were jailed. In a letter to Hammond released over the weekend, McDonnell said new allegations potentially implicating the Bank of England “demand an immediate response from this government”.