Everyone must wash their hands for the length of time it takes to sing the first verse of the national anthem, the deputy chief medical officer has said.
Dr Gina Radford warned that the majority of people did not wash their hands for long enough and many did not use soap.
Failure to carry out this 'basic hygiene' was causing people to pick up common infections and contributing to the growing problem of antibiotic resistance, she cautioned.
Her comments follow those of her boss, chief medical officer Professor Dame Sally Davies, who has been nicknamed the Government's 'nanny-in-chief' for her strict instructions about personal health.
She has told people not to drink any alcohol or tea and get off the bus a stop early. Earlier this month she ordered Britons to stop 'grazing' from the fridge.
Speaking at an International Longevity Centre debate in London on the problem of antibiotic resistance, Dr Radford said it could be combatted if everybody tried to avoid picking up infections in the first place.
Health chiefs have warned the overprescribing of antibiotics has caused bacteria to evolve into 'superbugs' which are immune to treatment. Experts fear it means infections could kill more people than cancer within a few decades.
But Dr Radford complained that most people did not help themselves or others because they did not bother to wash their hands properly after going to the toilet or before eating.
She said: 'Some of the prevention [techniques] are really simple things like hand-washing.
'On a day to day basis, you should wash your hands with soap and water for the length of one verse of God Save the Queen or two times through Happy Birthday.
'And I can absolutely guarantee that most of us don't do that. I know because I have observed - and I have observed myself. We don't do some of this stuff and we are not practising just some of the most basic hygiene.'
Singing the first verse of God Save the Queen or Happy Birthday twice takes between 30 and 45 seconds, depending on your singing speed. The version of the national anthem used in sporting events such as Formula 1 podium celebrations is 44 seconds long.
Dr Radford also warned doctors should not prescribe antibiotics 'inappropriately' and that patients should not ask for them for conditions like a sore throat, where nine out of 10 cases do not need the drugs.
She said there needed to be careful monitoring of the levels of the drugs used in farming, fisheries and even in paints - such as those used to paint ships to prevent barnacles growing.
'It is amazing the sorts of things we are doing to the eco-system which are affecting antimicrobial resistance,' she added.
Health officials have a goal of reducing the amount of antibiotics prescribed by GPs in the UK by 4 per cent in five years.
Over the past century, the development of effective antibiotics has seen the number of deaths caused by infection drop from 40 per cent of all deaths to just 7 per cent of deaths.
But once bacteria evolve to become resistant, the drugs become useless and even a minor graze could lead to a potentially-fatal infection.
There is already a year-on-year increase in bacteria which are resistant to drugs, including E. coli and the 'superbug' Klebsiella, which can cause pneumonia and meningitis.
Dame Sally has described antibiotic resistance as posing a 'catastrophic threat' which is as 'big a risk as terrorism' and would take healthcare back to the 19th century.
Earlier this year, she said 50,000 people a year were dying across the US and Europe from infections which were no longer possible to treat with antibiotics.
In an earlier interview, she said: 'Antimicrobial resistance poses a catastrophic threat. If we don't act now, any one of us could go into hospital in 20 years for minor surgery and die because of an ordinary infection that can' t be treated by antibiotics. And routine operations like hip replacements or organ transplants could be deadly because of the risk of infection.'