A little-used piece of wartime legislation has taken centre stage in the increasingly bitter battle between Donald Trump and critics who accuse the president of not doing enough to fight coronavirus.

As supplies of equipment such as protective masks and hospital ventilators have run low, Democrats and even some Republicans have criticised the president’s reluctance to use the Defense Production Act, under which he can compel companies to make certain products.

On Thursday, Chris Murphy, a Democratic senator from Connecticut, warned: “The problem is that the private sector supply chain has broken down. It is a ‘Lord of the Flies’ situation today in which supplies are not heading to areas of need but are instead heading to places where the money is or where the political connection is.”