Covid testing firms are facing a shortage of lateral flow tests, says Transport Secretary Grant Shapps.
The travel industry has called on the government to confirm when in October the rules will be changed.
Shapps said it would take several weeks to switch from PCR tests to lateral flow tests.
Addressing the Transport Select Committee, he said the Department of Health was responsible for making the decision.
However, he stressed that his colleagues were aware of school half-term dates and understood the speed required to implement this change.