At least 30,000 people will receive home blood type testing kits as the NHS tries to identify 5,000 individuals with critical O negative blood.

The first 6,000 kits will be posted by NHS Blood and Transplant this week to people who recently registered to be a blood donor but have not yet made their first appointment.

Those found to have O negative blood will be offered priority appointments to help ensure they become long-term donors.

The NHS said it is the first-ever mass home blood type testing campaign in the UK.

The search will widen out if needed and kits will be posted to up to 100,000 people registered with Give Blood over the coming months, until enough people with O negative blood are identified and booked on to donate.

It is the first time that the method of using large-scale home test kits to identify people with a certain blood type and booking them on to priority appointments has been trialled by the NHS.

The kit is a simple finger prick test, with a few small drops of blood, a litmus-test style card and a chart to match up results being all that is needed to find out a likely blood type in five minutes.

O negative blood is particularly valuable because it is the “universal donor” type which can be given to almost anyone, making it especially valuable in emergencies when there is no time to test a patient’s blood type.

Around 13% of hospital requests is for this type yet only 8% of the population have it.

David Rose, director of donor experience for NHS Blood and Transplant, said: “Patient needs and medical advances are changing, and already certain blood types are needed more often than others.

“We need an ever-growing share of our blood donors to be O negative to meet rising hospital demand for this type.

“If your blood type is known by us and you have the universal O negative, we can book your first appointment as a priority to save up to three lives and help keep blood stocks resilient this winter.

“This innovative new home testing kit could be key to helping newly-registered donors understand if they have the in-demand O negative blood type and that we would like them to act and book their first appointment as soon as possible.”