A number of MPs have expressed "alarm" at differences in testing rules between Wales and England.
In a letter to the First Minister, Welsh Conservative MPs accused the Welsh Government of putting care home residents at "unacceptable ongoing risk" for their decision not to routinely test people, regardless of whether they have symptoms.
It was agreed that critical workers were eligible for testing in Wales, following an announcement by England's health secretary Matt Hancock last week, but there are certain people, like the over 65s, who can get tested in England, but not in Wales.
The letter, signed by MPs, including former Welsh Secretary Alun Cairns, calls for "rapid action" to make sure the testing availability matches the rest of the UK.
It reads, "This is very disappointing, and comes in the wake of failings in the dispatch of shielding letters, difficulties for the vulnerable in obtaining priority supermarket assistance... reporting errors for Covid deaths... and delays in the replication of various UK Government schemes."
The other difference lies in how people can book a test, with millions in England being able to book a test online via the UK Government website. The Welsh online booking website is not a public site, and a link is sent to eligible workers by their employers, and only for those who qualify to get tested at the Cardiff or Newport sites.
Mark Drakeford has already defended not providing coronavirus tests to everyone in care homes saying "clinical evidence tells us that there is no value in doing so."
Wales' Chief Medical Officer spent much of Wednesday explaining why testing people in care homes without symptoms did not necessarily stop the spread and highlighted that people testing negative would have to be tested every day.
In response to the letter, a spokesperson said the government is "saddened" to receive such a letter when ministers are working "constructively with their counterparts from other parties."
"We are saddened to receive such a letter from Welsh Conservative MPs, which contains so many factual inaccuracies and misrepresentations. Our testing policy is based on scientific evidence and is focused on those who need a test most.
"People being admitted to hospital with symptoms; people being admitted to and transferred between care homes; care home residents and our frontline health and social care workers. We have also extended testing to critical workers, publishing our plan and our reasons for it.'