The UK government insisted it was on track to deliver tens of thousands of ventilators for treating coronavirus patients as it faced mounting criticism over its procurement plans and warnings that struggling hospitals may have to wait weeks for the critical devices.

Chris Hopson, chief executive of National Health Service Providers, on Thursday said a shortage of ventilators was already a “real issue” for hospitals in London, which is the epicentre of the Covid-19 outbreak in the UK.

He told the BBC’s Today programme that hospitals in the capital were struggling with an “explosion” of demand and faced a “continuous tsunami” of seriously ill patients. He later warned that in “three or four places, it's clear that they [hospitals] will run out of critical care capacity, probably by the weekend”.