NHS staff have called on Boris Johnson to ensure that new coronavirus testing centres are located conveniently for health workers and not in out-of-town sites like Ikea car parks.

Drive-in test centres for nurses and doctors were opened this week in converted car parks at the Scandinavian superstore in Wembley in London and Chessington theme park near the M25. But as hundreds queued for the swab tests, concern was raised that they were too far from work or home for tens of thousands working in the capital.

“Thousands of anxious NHS and care staff are in isolation, unsure of whether it’s safe to work. Test centres must be as convenient as possible to enable health workers to attend easily without adding further risks as they travel,” said Sara Gorton, head of health at the staff union Unison.

There was also some disappointment that the tests would not give staff an overnight green light to return to work. Most were told to expect results in three days’ time.

One nurse who had been self-isolating for 10 days said she was relieved to have been tested, but had hoped to be cleared to return to work sooner. “I want to go back to work, but I will have to wait longer now,” said the nurse, who works at the nearby Park Royal Centre for Mental Health.

“Speed is of the essence with results, to ensure staff who’re negative can get back to treating patients, and that tests remain valid. Locations, wait times and frequency of testing are among the many issues that need urgent attention,” said Gorton.

It is estimated that as many as 20% of the NHS workforce need testing urgently as they are either self-isolating because they have experienced symptoms or someone in their household is suspected as having the virus.

But just over 5,000 of 500,000 health workers in England have been tested because of the lack of diagnostic facilities in the UK compared to countries like Germany, health secretary Matt Hancock conceded.

Test sites will be rolled out across the country in the next week but so far the government has not disclosed their location.

In Northern Ireland, the transport minister revealed she would make MOT centres available, while in Wales a new centre at the Rodney Parade rugby stadium in Newport will be used for testing.

Hancock pledged to quadruple the testing target to 100,000 a week by the end of April and revealed the government would be teaming up with Boots and Amazon which can bring logistics heft to the coronavirus battle.

The lack of testing and supply of personal protection equipment has been the source of significant stress for those at the centre of the crisis.

One doctor who got tested at the Wembley centre on Thursday, said he worked “at the heart” of the crisis Northwick Park Hospital. “There hasn’t been enough testing, and it is definitely causing stress and anxiety,” he said.

The testing centre in the Ikea car park dealt briskly with the long queues, with marshals estimating they had dealt with 180 in the first hour and a half, putting it on course to collect swabs from around 1,000 people over the course of the day.

But there was some confusion, and one nurse was initially turned away after making the 10-mile journey. Marites Vincencio, a nurse at Chelsea and Kensington Hospital, said she had phoned the testing hotline and was told to show up at Ikea at 10am, but had received no email to support her case.