Puffing on an asthma inhaler cuts three days off the length of time people are taking to recover from a bout of Covid-19, boosting hopes that lockdown restrictions will end for good on July 19.
The findings have led to doctors prescribing inhalers to Covid sufferers on "a case-by-case basis, ministers disclosed to MPs late last week.
The news came as Matt Hancock told MPs that people who catch coronavirus are now spending 20 per cent less time in hospital beds as the vaccine roll-out continues.
MPs hailed the double boost as further evidence that hospitals can cope with any surge in cases caused by the spread of the Indian or Delta variant.
But Sir Graham Brady, a senior figure in the Covid Recovery Group of Tory MPs, questioned whether the Government should make more use of inhalers among those suffering from Covid-19.
He said: "If the average length of stay in a hospital is now eight days, and you can reduce that by three days typically by using inhalers, why the hell haven’t they done that?"
In a Parliamentary answer Health minister Jo Churchill disclosed that a Government study had found "inhaled budesonide reduced the time to self-reported recovery by a median of three days".
Inhaled budesonide had been trialled among non-hospitalised Covid patients who are 65 years old and over or 50 years old and over with an underlying health condition earlier this year, she said.
Ms Churchill told MPs: "Clinical guidance has been issued for clinicians to consider prescribing inhaled budesonide on a case-by-case basis, but inhaled budesonide is not currently recommended as the standard of care in the UK."
Inhaled budesonide is a medicine used for asthma and chronic obstructive pulmonary disease and is taken using a brown or beige inhaler to stave off shortness of breath.
The minister added that the findings were currently only based on an interim results and "the full analysis is currently underway to understand the full benefit of this treatment".
"The Department will continue to monitor the results as more detailed data and analysis from the trial becomes available and stand ready to adjust guidance should this be appropriate," she said.
That came after Mr Hancock disclosed that patients who are contracting Covid-19 in the so-called third wave of the pandemic are spending 20 per cent less time in hospital.
The Health Secretary told MPs that "the best estimate I have is that the average length of stay for somebody in hospital owing to covid has fallen from 10 days to eight days, so it has fallen to a degree, but not a huge degree.
"That is partly because of treatments, but it is also partly because some of the people in hospital have had at least one dose of the vaccine, which is highly likely to have reduced the severity of the disease."
The disclosures were made to Sir Graham, the chairman of the 1922 committee of Tory MPs who has been a constant critic of the Government’s lockdowns.
Sir Graham told The Telegraph he was prompted to ask the questions after a local doctor had told him that his hospital had not treated a single "routine asthmatic" among it Covid-19 patients.
The doctor had said that the finding suggested that the steroid inhaler used by asthmatics regularly appeared to prevent the development of Covid-19 from a mild to a serious disease.
The Department of Health was approached for comment.