London’s ExCel conference centre will become an emergency hospital treating coronavirus patients “within days”, with 500 beds initially made available at what will be the first of several crisis facilities dotted around the UK.

The cavernous 100,000 sq metre Docklands site is being converted in a high-speed operation involving military planners and personnel, and its capacity will rise quickly from the initial 500 beds, defence sources said on Tuesday. It is intended to deal with the expected surge in coronavirus patients with severe breathing difficulties for whom beds are unlikely be available in London’s overflowing intensive care units.

“We will next week open a new hospital, a temporary hospital, the NHS Nightingale hospital, at the ExCel centre in London,” Matt Hancock, the health secretary, said at a news conference on Tuesday.

“The NHS Nightingale hospital will comprise two wards each of 2,000 people. With the help of the military and with NHS clinicians, we will make sure that we have the capacity that we need.”

Defence sources added that “more than one” emergency hospital would be built around the UK, although London is first because the rate of coronavirus infections is considered to be running 1.5 to 2.5 weeks ahead. “We will service and support the whole of the United Kingdom,” a source added.

The NEC in Birmingham has said it “stands ready” and is “well-equipped” should the centre be considered as a suitable location for a temporary hospital.

In a statement, a spokeswoman said: “We are and have been in constant communication with the local NHS trust, police and fire service, and the services are fully aware of the capabilities of the venue. We will do our utmost to support the effort in combating the virus.”

The Guardian revealed on Monday that the Excel centre would ultimately have capacity for about 4,000 beds, many of whose occupants will be anaesthetised, intubated and kept alive on a ventilator because their lungs have failed.

“They are there to deliver the gap, or part of the gap that has emerged between peacetime NHS capability and the stress that we’ve got on our system,” one insider said.

There are about 700 military personnel deployed in the UK to tackle the coronavirus crisis, including military planners around the country to help local emergency forums prepare for the anticipated surge in cases.

A further 2,000 of the 20,000 troops available in the UK have been placed at 24 hours’ notice to help with any urgent requests from civilian authorities, and a further 1,500 are on 48-hour standby.

There are at least 50 soldiers who started helping to deliver badly needed face masks, gloves and other personal protective equipment for the NHS from Monday, a figure expected to rise to 460 when deliveries get to full capacity.

But Ministry of Defence insiders said there was no expectation that the military would be needed on the streets to help maintain public order, arguing it was not even “the fourth, fifth, sixth or seventh” priority.

Police forces are confident they can enforce the lockdown ordered by Boris Johnson on Monday night, and the only circumstances where soldiers might be used is to guard strategic sites, such as nuclear power stations, to allow constables to be redeployed elsewhere.

The main focuses for military aid in the UK are expected to be in the medical and planning areas. Military medics who are not working in the NHS already will be expected to provide help and support to the health service, although they will have to be retrained to some extent to help treat patients suffering from coronavirus.