A leading surgeon has said NHS staff must be routinely tested for coronavirus up to twice a week.
Prof Derek Alderson, president of the Royal College of Surgeons, said it was vital, to reassure patients staff were not unwittingly carrying the virus.
But hospital trust bosses say they are still waiting for clarity on plans for regular testing.
The Department for Health and Social Care (DHSC) said it was focusing on routine testing in care homes.
Prof Alderson was speaking at a Health Select Committee meeting about the necessary steps to get all NHS services back up and running.
He said: "It's absolutely essential to regain public confidence that we are able to test our staff regularly."
It would be "pragmatic" for testing to take place "about twice weekly", he added, because it was known that the available tests were not perfect.
Multiple tests 'essential'
As many as 30% of infections could be missed by a single swab test, research from the University of Bristol suggests - giving an infected person a negative result.
So a negative result should not be treated as a guarantee, scientists say.
"It will always be essential to have multiple tests," Prof Nicola Stonehouse, a virologist at the University of Leeds, told the BBC.
"In addition to the challenges of accurate sampling, you can be fine one day and infected the next."
Experts are concerned about the possibility of asymptomatic spread, where staff don't know they are infected, but may still be capable of passing the virus on to others.
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The Department of Health and Social Care (DHSC) said it had capacity to carry out just over 200,000 diagnostic tests as of 15 June.
But only 75,935 of these tests were actually carried out.
"There is adequate capacity, it just needs to be directed to those who need it most," Prof Alderson said.
A staff testing pilot scheme was carried out across 11 hospital trusts more than a month ago, according to NHS Providers, which represents trust leaders.
"But we've had no results and no timeline," its deputy chief executive Saffron Cordery said.
"We have no idea when it will be rolled out."
As it stands, she said, there is no system in place to carry out weekly testing of health staff which she estimates will amount to more than 100,000 a day.
"It's a big issue if we want the NHS to get back on its feet," Ms Cordery said.
The government said care home staff and residents could be tested even if they don't have symptoms at the end of April, but it has not committed to routinely testing NHS workers.
A DHSC spokesperson said retesting would be "guided by clinical advice on relative priority and available testing capacity".
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