The deputy chief medical officer says clinical management of coronavirus patients must take priority over carrying out widespread testing for the virus.
Speaking during Thursday's government briefing, Dr Jenny Harries responded to concerns that not enough tests for the virus were being carried out.
Systems of widespread testing are thought to have been largely successful in countries including South Korea. And the World Health Organisation has previously said its key message to world leaders was 'test, test, test'.
Earlier this month, head Tedros Adhanom Ghebreyesus said testing, isolation and contact tracing should be the "backbone" of the global response.