The coalition government derailed a programme that aimed to save lives by reducing the amount of salt in food and then gave industry too much power over a replacement scheme, according to health experts.

Stripping the Food Standards Agency (FSA) of its responsibility for nutrition in 2010 – a decade after Labour set it up – slowed progress in cutting premature deaths linked to high blood pressure, the experts claim in their paper in the BMJ.

Authors led by Graham MacGregor, professor of cardiovascular medicine at Queen Mary University of London, say salt content in foods was reduced by 10% to 40% over five years from 2006, when the first targets were set.

Since 2003, average salt consumption in the UK population fell by 15%, from 9.5g a day to 8.1g in 2011. The overall aim was eventually to cut salt intake to 6g a day.

The authors cite 2010 evidence from the FSA and National Institute for Health and Care Excellence suggesting the programme prevented 9,000 deaths a year in the UK from strokes or heart disease and resulted in healthcare savings of £1.5bn a year.

But there were problems over fixing new salt reduction targets after nutrition issues returned to the health department.

MacGregor, unpaid chairman of the campaign charity Consensus Action on Salt and Health (Cash), and colleagues, one a Cash member, the other an employee, say the new “responsibility deal” with the food industry was “a major step backwards in public health nutrition”.

A further 6,000 deaths a year from heart attacks or strokes might have been prevented if the reduction programme had not been interrupted before resuming under an industry-dominated committee.

Last year, targets for reducing salts in different foods were eventually set for 2017 under the deal with industry. The Department of Healthsaid that reducing salt intake in adults by just a gram a day would prevent nearly 4,150 premature deaths a year in the UK.

But these new targets do not have the backing of big companies such as Unilever, McDonald’s and Kellogg’s, the authors say.

The authors said: “The food industry does not think they or their competitors need to comply as there is no enforcement or proper monitoring of the programme.

“It is vital that health professionals, politicians and the food industry are made more aware that the food we eat is currently the biggest cause of death and ill-health in the UK.

“It is therefore imperative that responsibility for nutrition be handed back to an independent agency, which is not affected by changes in government, ministers or political lobbying.”

A Conservative party spokesman said: “The UK now has the lowest salt intake of any developed country and our work on salt reduction is world-leading. Through voluntary action with industry, we have been able to go further and faster than regulations could.

“Three quarters of the retail market and 60% of major high street restaurants have committed to reducing salt intake which will help people make healthier choices when they buy food or eat out.”

Luciana Berger, shadow minister for public health, said: “The scale of the challenge we are facing is too great to rely solely on a non-binding and piecemeal deal with a select group of companies.

“This is why Labour will stand up to vested interests and take decisive action to give each child a healthier start in life including setting maximum limits on sugar, fat and salt in food that is marketed substantially to children.”

Norman Lamb, the Lib Dem health minister, pledged his party would give more information about salt in food through traffic light labelling on packaging and more information on restaurant and takeaway menus.

“We will restrict advertising of products high in salt on TV before the watershed to prevent them being advertised to children.’’

The McDonald’s burger chain said it had worked “continuously” to adapt recipes to remove salt, sugar and fat without changing the taste and provided information about the nutrition and calorie content: “Since 2004, we have reduced salt in our chicken McNuggets by 30%, french fries by 24% and ketchup by 23%. Customers can request for no salt to be added to our burgers and fries.”

Kellogg’s said that over the past 16 years it had reduced salt by around 60% in breakfast cereals, which contributed just 2% of the total salt in people’s diets.

“We face a number of technical challenges in reducing it further in our cereals. Until we have a fix for these challenges, we won’t sign up to something we know we can’t deliver,” it said.

A Unilever spokesman said: “Our global salt reduction strategy is based on a 5 gram intake per day by 2020. We are making good progress on this in the UK with around 90% of products (by volume) meeting this target.

“Consumers are accustomed to salt and levels need to be reduced gradually to allow taste preferences to adjust. Technological investment and innovation is also required to make reformulation possible.”

Barbara Gallani, director of regulation, science and health, at the Food and Drink Federation industry body, said: “It’s common sense that food producers should be involved in shaping a salt reduction strategy as only a thorough understanding of ingredients and recipes can result in stretching but realistic targets.

“Having made great early strides to reduce salt in products, many companies are finding reductions harder to achieve without compromising product safety or jeopardising taste, texture or shelf life.”