Home testing kits are to be sent out to people in their 60s in a bowel cancer screening programme for England, the government has announced.
Bowel cancer kills around 14,000 each year
The tests will identify those who may have the disease, the second largest cause of cancer death in the UK.
By 2009, everyone aged 60-69 will be asked to self-test every two years.
The government hopes the privacy and dignity of the home testing kits will overcome people's natural reluctance to talk about symptoms.
People taking part in the scheme will send stool samples to a laboratory, where they will be analysed for the presence of blood.
The programme, promised in the 2000 NHS Plan and which will cost £37.5m in its first two years, is to be phased in from April 2006.
Around 25% of England, or 300,000 people, will be covered in the first year of the programme.
By 2009, the aim is for two million to receive the kits annually.
Five centres, which will include testing laboratories, are to be set up around the UK to analyse the kits.
Strategic Health Authorities are being invited to bid to provide a first wave of local screening centres.
Bowel cancer kills 50 people a day in the UK. Lung cancer is the only form of the disease which kills more people.
Ministers believe a screening programme could cut the death rate by 15%.
Launching the programme, health minister Rosie Winterton said: "Although bowel cancer affects more than one in 20 people in their lifetime, of those who get the disease 90% survive if it is caught early.
"Because of the nature of the disease, people can feel uncomfortable talking about it, let alone coping with the symptoms.
"That is why the privacy and dignity that the home testing kits afford will help us better tackle the disease."
Jerry McMahon, of Kingsbury in Middlesex, was called in for screening under a pilot scheme at Northwick Park Hospital.
Mr Mahon, now 62, had no symptoms to suggest anything was wrong.
But a colonoscopy found two polyps in his colon, one of which was found to be cancerous.
He said: "The test was a life-saver. I've nothing but praise for the doctors at Northwick Park. I feel better now than I did at 25."
Hilary Whittaker, chief executive of the national charity Beating Bowel Cancer, said: "We believe that the screening programme will be a positive step in reducing the number of deaths from this cancer."
Neil Brookes, chief executive of Colon Cancer Concern, said: "At a stroke, the screening programme will raise the profile of the disease and encourage people to be much more active in seeking to prevent it."
TV presenter Lynn Faulds-Wood, of Lynn's Bowel Cancer Campaign and chairman of the European Cancer Patient Coalition, said: "I survived advanced bowel cancer and I've been investigating how to help save lives from bowel cancer for years. Screening, in my opinion, is the best way."
Professor Elwyn Elias, president of the British Society of Gastroenterology, welcomed the programme, but said the NHS would have to be able to cope with the people flagged up as needing further checks.
"If this is going to go national, which is obviously the aim, it will need a lot of investment and doctors will need a lot of training."