The treatment uses a protein called interferon beta which the body produces when it gets a viral infection.

The protein is inhaled directly into the lungs of patients with coronavirus, using a nebuliser, in the hope that it will stimulate an immune response.

The initial findings suggest the treatment cut the odds of a Covid-19 patient in hospital developing severe disease - such as requiring ventilation by 79 per cent.

Richard Marsden, CEO of Synairgen, said: "We are all delighted with the trial results announced today, which showed that SNG001 greatly reduced the number of hospitalised Covid-19 patients who progressed from ‘requiring oxygen’ to ‘requiring ventilation’.

“It also showed that patients who received SNG001 were at least twice as likely to recover to the point where their everyday activities were not compromised through having been infected by SARS-CoV-2.

“In addition, SNG001 has significantly reduced breathlessness, one of the main symptoms of severe Covid-19.

“This assessment of SNG001 in Covid-19 patients could signal a major breakthrough in the treatment of hospitalised Covid-19 patients.

“Our efforts are now focused onworking with the regulators and other key groups to progress this potential Covid-19 treatment as rapidly as possible."

The scientist in charge of the trial, Tom Wilkinson, says if the results are confirmed in larger studies the new treatment will be "a game changer".

The double-blind trial involved 101 volunteers who had been admitted for treatment at nine UK hospitals for Covid-19 infections.

The results have not been published in a peer-reviewed journal, nor has the full data been made available.