Teachers are “likely” to be given priority access to coronavirus tests alongside other “frontline” workers, the government has confirmed.

Health minister Edward Argar said on Thursday morning as demand for tests increased, they would be rationed based on people’s jobs.

“It’s right that we prioritise the frontline,” he told BBC Radio 4′s Today programme.

“Teachers are likely to be in that priority group. They are frontline workers.”

Argar said the full list of who would get priority for a test would be published in the “next few days”.

He said the change in approach would likely mean some people who have symptoms would have to “wait longer” than others.

“As we see demand increasing, yes, there is a challenge for capacity there,” he admitted.

His comments come as research suggests up to 25,000 teachers in England may be self-isolating amid a shortage of tests. The Guardian reported that a survey of 6,700 teachers by the Teacher Tapp app found 4% were isolating from school for Covid-related reasons on Tuesday.

It comes as Boris Johnson warned actions to stop a second surge of coronavirus must be “tough now” in order to “protect” Christmas.

Stricter new measures are expected to be announced today for the North East of England, where cases are on the rise – including a reported curfew on pubs.

The PM said people have to be “both confident and cautious” and that it is “crucial” the country does not re-enter “some great lockdown again that stops business from functioning”.

He told The Sun: “Christmas we want to protect, and we want everyone to have a fantastic Christmas.

“But the only way to make sure the country is able to enjoy Christmas is to be tough now.

“So if we can grip it now, stop the surge, arrest the spike, stop the second hump of the dromedary, flatten the second hump.”

In south Wales, a local lockdown will come into force from 6pm on Thursday, meaning people must not enter or leave the Rhondda Cynon Taf area without a reasonable excuse.

Under new rules, licensed pubs, bars and restaurants in the area will have to close at 11pm – and meetings with other people indoors will not be allowed, including for extended households.

The spikes in infection rates came as Johnson admitted there is not enough capacity in the system after demand “massively accelerated” in recent weeks.

He told MPs at the Liaison Committee on Wednesday: “We don’t have enough testing capacity now because, in an ideal world, I would like to test absolutely everybody that wants a test immediately”.

He said the virus was spreading from the young to the more vulnerable elderly, with the rate of cases among the over-80s doubling in just days – and warned that would “lead to mortality”.

This afternoon, Baroness Dido Harding, who is interim executive chair of the National Institute for Health Protection – and oversees the NHS Test and Trace system, is due to give evidence to the Commons Science and Technology Committee.

Following the publication of the latest test and trace figures last week, the Tory peer insisted the system was “working” despite key targets being missed and the number of close contacts being reached falling to a record low.

It was revealed earlier this week that tests will have to be rationed while the government struggles to get to grips with soaring demand.