Time is running out to finalise a track and trace strategy that would avoid a potential second surge in coronavirus cases, NHS leaders have said.
The NHS Confederation warned of “severe” consequences to staff and patients if the right system was not established rapidly.
It said lockdown measures should not be eased until a clear plan was in place.
It follows the PM’s pledge on Wednesday to introduce a “world-beating” contact tracing system in England from June.
Contact tracing identifies those who may have come into contact with an infected person so they can avoid potentially passing the disease on.
Niall Dickson, chief executive of the confederation, which represents health and care leaders, welcomed Boris Johnson’s commitment, made at Prime Minister’s Questions on Wednesday.
But in a letter to Health Secretary Matt Hancock, Mr Dickson said without a clear strategy the UK was at greater risk of a second peak of the virus.
“We are 10 weeks into the pandemic and developing a strategy with a well worked through local base should have been in place much sooner,” he said.
“If we do not rapidly instigate the right system, involving the right people, then the ramifications for the NHS, including its staff and its patients, could be severe.”
On Wednesday, Mr Johnson said 25,000 contact tracers, able to track 10,000 new cases a day, would be in place by 1 June.
It coincides with the earliest possible date for the gradual reopening of schools and non-essential shops in England.
Northern Ireland already has a telephone contact tracing system in place, while the Scottish government is currently trialling one. The Welsh government wants its programme operational by the end of May.
One of the government’s most senior scientific advisers previously said an effective tracing system needed to be in place before lockdown restrictions could be changed.
What this letter indicates is that, for all the rhetoric, the NHS Confederation does not yet believe that the government has a robust plan for virus testing and tracking of contacts of those who are infected.
And that comes even after the prime minister’s statement that such a programme will be in place by 1 June with 25,000 contact tracers appointed.
A widespread testing and tracing system is seen as a necessity if lockdown restrictions are to be further eased, including the reopening of schools.
The confederation, which represents health leaders and organisations in England, Wales and Northern Ireland, does welcome Mr Johnson’s commitment to a testing and tracing programme.
But tellingly it notes that its members are not yet reassured, and that if there is not rapid action there could be a second wave of infections and serious consequences for NHS patients and staff.
Contract tracing for coronavirus began when the UK identified its first two cases at the end of January.
But it was stopped in mid-March after England’s chief medical officer, Prof Chris Whitty, said it was “no longer necessary for us to identify every case”.
On Wednesday, Labour leader Sir Keir Starmer challenged Mr Johnson over that decision, describing it as a “huge hole in our defences”.
In response, the prime minister said he was “confident” that England would have a test-and-trace operation which would allow the country to make “progress”.
Latest figures show the total number of people who have died after testing positive for coronavirus in the UK has reached 35,704.