A consistent system of front-of-pack food labelling will be introduced in the UK next year, the government says.

A combination of guideline daily amounts, colour coding and "high, medium or low" wording will be used to show how much fat, salt and sugar and how many calories are in each product.

The scheme will be voluntary, but ministers are confident they have the food industry on board.

Talks will take place later this week over the exact design of the labels.

If those discussions go well it could mark the end of what has been a long-running campaign to introduce front-of-pack labelling.

The issue has been under discussion for the past decade with campaigners seeing it as a way of tackling the rising rates of obesity.

But the introduction of a consistent system has proved difficult, and instead a range of different labels have gradually been introduced over the years.

Analysis Despite the government's confident announcement, this is still not quite a done deal. Within the food industry - and particularly among manufacturers rather than the supermarkets themselves - there are still grumblings about front-of-pack labelling. But after years of discussions and research and a detailed consultation over the summer, ministers are effectively sticking their necks out to force the sector over the line. Talks are due to take place on Thursday and by making this announcement now it puts the pressure on industry representatives to sign up. If a consistent system is not in place by the summer of next year the government will feel it can lay the blame elsewhere.

Some retailers and manufacturers have used "traffic-light" labelling, in which the least healthy foods are labelled red and the most healthy are in green, while others use guideline daily amounts - or GDAs - which give the percentage of recommended intake. Some use both.

There has also been confusion over how a system could be introduced.

To make it mandatory, regulations would have to be agreed on a European level, but agreement between countries has been hard to reach.

The situation meant the UK government sought to introduce a voluntary system.

It carried out a consultation on the issue over the summer, which paved the way for this announcement.

What the new labels might look like Consumers prefer the traffic light system because it offers key information 'at a glance', according to a Food Standards Agency study.

The GDA system is based on percentages of daily value for fat, sugar, and salt. The study suggests GDA proponents prefer more information over the simplistic colour coding system.

For each nutritional category there are specfic high, medium and low ranges that are based on recommended daily values.

Public Health Minister Anna Soubry said: "The UK already has the largest number of products with front-of-pack labels in Europe, but research has shown that consumers get confused by the wide variety of labels used.

"By having a consistent system we will all be able to see, at a glance, what is in our food. This will help us all choose healthier options and control our calorie intake.

"Obesity and poor diet cost the NHS billions of pounds every year. Making small changes to our diet can have a big impact on our health and could stop us getting serious illnesses - such as heart disease - later in life."

She said she expected the new system to be in use by the summer of 2013.

Prof Alan Maryon-Davis, an expert in health promotion from King's College London and a former president of the UK Faculty of Public Health, said: "This is welcome news - at long last.

"The Food Standards Agency recommended this scheme years ago - but a few big retailers succeeded in blocking it until now.

"This is a triumph for public health and common sense - but just goes to show how the voluntary approach can be so much slower than government regulation."

But Barbara Gallani, of the Food and Drink Federation, said the industry in the UK had "led the way" on the issue.

She added: "Our members are committed to continuing to provide clear nutrition information to consumers and we well be actively engaged in further discussions with the Department of Health following today's announcement."