The health secretary, Sajid Javid, has warned MPs he may need to “constrain” the Covid testing system over the next fortnight, as demand for lateral flow kits surges.
Ministers have repeatedly encouraged members of the public to test themselves using a lateral flow device (LFD) before attending gatherings or meeting vulnerable relatives.
However, test kits have repeatedly been unavailable online in recent days, and many pharmacies have complained of being unable to secure them.
Labour has accused the government of presiding over a “shambles”, with many members of the public struggling to obtain tests despite ministers putting testing at the centre of efforts to control the spread of Omicron.
Demand for the tests has also been boosted by a change in quarantine rules that allows people to emerge from self-isolation after seven days instead of 10, as long as they carry out two negative lateral flow tests.
In a letter sent to MPs on Wednesday evening, Javid acknowledged the intense strain being put on the system as cases of the Omicron variant continue to increase, with 183,037 new infections recorded on Wednesday.
“In light of the huge demand for LFDs seen over the last three weeks, we expect to need to constrain the system at certain points over the next two weeks to manage supply over the course of each day, with new tranches of supply released regularly throughout each day,” he wrote.
Javid reiterated the advice that the public should take a test “when engaging in activities that carry the greatest risk, and before coming into contact with people at risk of serious illness”.
He said MPs should suggest that constituents unable to source testing kits online or find any at their local pharmacist, should, “see whether their local authority is distributing tests” or seek them out at local community facilities, such as libraries.
“I would like to thank your constituents for their continued understanding and patience during this unprecedented time,” he wrote.
Javid underlined the action the government has taken to increase the supply of LFDs, with 300m expected to be available in January, up from the 100m planned before the Omicron variant was discovered.
Amid warnings that the PCR tests used to confirm new cases of the virus have also been unavailable in many parts of the country, Javid also stressed that capacity for these has increased significantly, from 530,000 a day in November to up to 700,000 a day.
Unlike in Scotland, Wales and Northern Ireland, ministers at Westminster have opted not to place new restrictions on the public before new year.
There is mounting concern among NHS leaders about their capacity to deal with surging cases, however.
Data published on Wednesday showed there were 10,462 patients in hospital with Covid in England. That was the highest figure since March, although it is unclear how many were admitted with the disease and how many are there for another reason while also testing positive.