The health secretary, Matt Hancock, has announced the coronavirus infection survey is to increase from regularly testing 28,000 people per fortnight in England to 150,000.

The Office for National Statistics (ONS) survey ultimately aims to include 400,000 individuals, the Department of Health and Social Care said.

The expansion aims to have 150,000 people tested per fortnight by October, and the survey extended to cover Scotland, Wales and Northern Ireland.

Hancock said: “We are developing the capacity to test for coronavirus on an unprecedented scale and undertaking one of the biggest expansions of surveillance testing we have ever seen.

“This ONS survey will be a crucial part of this work – improving our understanding of the rate of infection in the population and how many people have antibodies.

“This will allow us to further narrow down the areas potentially affected by local outbreaks and continue our fight to curb the spread ahead of winter.

“The data and insight gathered will help inform our national, regional and local responses to the pandemic, allowing this nation to get back to the things we love doing.”

It comes as Heathrow airport unveiled a new coronavirus testing facility that it hopes will lead to the end of the mandatory 14-day quarantine for those returning from certain countries.

Arriving passengers will be able to book swab tests and have results sent to them in seven hours under the proposal, which is being used in Germany and Iceland.

Travellers can take a second test at home a few days later and then leave quarantine early if they pass both checks, the Daily Mail reported.

Heathrow executives hope those testing negative could leave quarantine five to eight days after landing, though the airport’s programme needs government approval before it can begin.

Documents released on Friday from Sage’s 18 June meeting showed the scientific group found “double testing of travellers significantly reduces the risk of false negatives and could enable quarantine duration of less than 14 days”.

Meanwhile, ONS analysis published on Tuesday found only 28% of people testing positive for Covid-19 reported any evidence of symptoms at the time of their swab test or at either the preceding or subsequent tests.

The remaining 72% of positive cases either did not report having any of the specific or general symptoms on the day of their positive swab test, preceding or subsequent swab tests or did not answer both questions, the ONS added.

It said the findings suggested that there was a potentially large number of asymptomatic cases of the virus.