There has been a "shocking" rise in the salt content of food in people's shopping baskets, with major brands at fault, according to a new study.
Despite dozens of firms signing up to a voluntary deal to cut salt levels, health campaigners said too many everyday foods still contain too much salt.
Research from the Consensus Action on Salt and Health (Cash) found that products such as tinned tomato soup, cheddar cheese and chilled ready meals are among the worst offenders for increasing salt in recent years.
Almost half (47%) of the 45 soups Cash surveyed contained the same amount of salt or more per serving than two slices of Domino's cheese and tomato pizza.
The saltiest soup tested was Baxters vegetarian Italian tomato and basil, with 3.5g salt per 400g can. This contains more salt than a McDonald's Big Mac and large fries (just over 3.1g), the research found.
The review of tinned tomato soup from 2007 and 2016 found 55% of the products contained the same amount of salt or more than in 2010.
Soups with some of the biggest increases were Tesco Everyday Value tomato (50% increase from 0.4g/100g to 0.6g/100g), Baxters Favourites cream of tomato (40% increase from 0.5g/100g to 0.7g/100g) and Sainsbury's Basics cream of tomato soup (25% increase from 0.48g/100g to 0.6g/100g).
Cash also looked at the salt content of 201 blocks of cheese and found that salt levels have hovered around 1.8g per 100g since 2006.
But some products have seen an increase in salt, with Sainsbury's Lighter mature British cheese increasing 16% from 1.7g/100g to 1.98g/100g since 2012.
Morrisons medium cheddar has also seen salt levels rise 13%, from 1.6g/100g to 1.8g/100g.
Meanwhile, when it comes to ready meals, the Cash survey found the salt content per 100g of cottage pie - from 42 meals tested - slightly increasing from 0.52g in 2007 to 0.54g in 2016.
Sainsbury's Basics cottage pie now has higher salt levels (up 186%), from 0.5g to 1.43g per 300g serving.
The Co-operative Truly Irresistible cottage pie also saw a 93% rise in salt, from 1.5g to 2.9g per 400g.
Cash also pointed out that luxury ready meals have high salt content, with the Marks & Spencer's Gastropub cottage pie in rich red wine gravy with cheese mash having 2.9g of salt per 400g serving.
And while progress has been made to cut salt in breakfast cereals, some firms have increased salt in their products.
Cash found that the salt content of Sainsbury's cornflakes increased 42% from 0.74g/100g to 1.05g/100g in recent years.
Kellogg's cornflakes have the highest salt content of all cornflakes surveyed, with three times more salt than Aldi's harvest morn cornflakes (1.13g/100g compared to 0.34g/100g).
Graham MacGregor, professor of cardiovascular medicine at Queen Mary University of London and chairman of Cash, said that under an old scheme run by the Food Standards Agency (FSA), with involvement from Cash, the UK led the world in salt reduction.
He said the Responsibility Deal run by the Department of Health - where firms sign up to a voluntary code to cut salt in food - was not working.
He said: "It is a tragedy for public health that the coalition government in 2010 seized responsibility for nutrition from the FSA to the Department of Health where they made the food industry responsible for policing themselves.
"Unsurprisingly, this has failed and has resulted in many thousands of unnecessary deaths from strokes and heart disease.
"It's imperative that responsibility for nutrition be handed back to an independent agency where it is not affected by changes in government, ministers, political lobbying and pressure from the food industry."
Sonia Pombo, nutritionist and campaign manager for Cash, said: "Whilst many food manufacturers initially made a concerted effort to reduce the salt in their products, others are now failing to do so and, in turn, are putting the nation's health at risk.
"To do this, an agency independent of political control and not run by the food industry needs to set regulated targets for salt, saturated fat and sugar to give the food industry a level playing field."
Barbara Dinsdale, lifestyle manager for the charity Heart Research UK, said: "How unfortunate that the huge progress made by the food industry in reducing salt levels whilst under scrutiny from the independent Food Standards Agency has lost momentum since the introduction of the Responsibility Deal.
"Heart disease is still the biggest preventable cause of death in the UK and we know from the successes already achieved between 2004 and 2010 that consumer tastes can adapt to lower salt alternatives.
"It's important for the collective health of the nation to ensure that salt reduction targets are effectively policed to reduce the burden of ill-health caused by consuming too much salt."