Environment secretary Owen Paterson has described the horse meat scandal as "wholly unacceptable" and urged food providers to work quickly to regain customer confidence.
The government minister's comments came following the publication of the latest DNA test results by the Food Standards Agency.
"My concern is for consumers," said Paterson (pictured). "The news for them today is that the vast majority of products tested are completely clear of horse DNA.
"Food businesses now have a lot of work to do. They need to move quickly to complete these tests and they need to show their customers they've taken the right steps to make sure this doesn't happen again."
Compass Group, Brakes and Booker Group have pledged to "do whatever it takes to restore public confidence in the food they buy and eat" as more revelations in the on-going horse meat scandal continue to surface.
It was revealed today that tests for horse meat by Compass Group, hotel and restaurant group Whitbread, and a Lancashire County Council's school meals service have come back positive.
Richard Cousins, chief executive of Compass, Brakes boss Philip Jansen and Charles Wilson of Booker, were among the signatories of an open letter from food service providers and retailers to consumers.
It said: "Food shoppers expect that the products they buy from retailers and manufacturers contain the ingredients on the label. They are right to be concerned that in a small number of products this is not the case. We understand and share their anger and outrage.
"The food industry is determined to restore consumer confidence in the food we sell as quickly as possible. We can't accept a situation where the trust customers place in us is being compromised by fraudulent activity or even as alleged, an international criminal conspiracy.
"That is why we are acting together with the Government and the Food Standards Agency, not only to get to the bottom of how this has happened but to take whatever steps are necessary to reassure customers that they can trust the food they buy.
"We are working around the clock to complete the most comprehensive testing of processed beef products ever undertaken, anywhere in the world. We are openly sharing the results of these tests and acting immediately to withdraw any product where there is any doubt as to its authenticity.
"British retailers, manufacturers and wholesalers already have some of the most rigorous testing and auditing systems in the world but we will be re-strengthening these to ensure that every part of the supply chain is in no doubt of the obligations we all share to the consumer.
"Nothing is more important to us than our consumers' trust. We will do whatever it takes to restore public confidence in the food they buy and eat."
Of the 2,501 products tested by the FSA, none were found to contain more than 1% horse meat.
The FSA said the 29 positive results were on seven previously withdrawn products and its chief executive Catherine Brown said she remained "confident" that the testing was the right way to tackle the issue.
"It will take some time to complete the process and is costly for the industry. But it is industry's responsibility to get this right - not the government's - and we consider that a comprehensive testing programme at all points of the supply chain and in all sectors is an essential step in addressing this issue," she said.
"And as this programme of testing and publishing results continues, and as action is taken to tackle this issue in supply chains across Europe, we will reach the point where we can say with confidence that horse meat is no longer illegally entering the UK food chain."
There is still speculation surrounding the root cause of the scandal but ultimately the discovery of horse meat in products labelled as beef has forced food service providers and manufacturers to re-assess their supply chains.
Paul Connelly, director of purchasing at buying consortium Beacon, said that challenging economic times with high levels of inflation can often lead price to be the primary factor in sourcing food providers.
"For some operators product origin and traceability may be secondary considerations," he said.
"However the recent horse meat issue highlights the fundamental importance of supply chain assurance, and the need for operators to provide prompt and unequivocal information to their own customers around supplier accreditation and due diligence.
"We would always advise operators to follow a vigorous supplier selection and due diligence process, ensuring food providers are fully accredited to BRC or similar standard and are actively managing product traceability."
A number of other contract caterers that have proactively sought reassurances from suppliers over their meat products.
Amadeus managing director Kevin Watson said all of the company's suppliers had provided statements assuring no products supplied to Amadeus are implicated in the equine DNA contamination.
Aramark has received confirmation from its approved suppliers that their products do not contain horse meat, and emphasised that it only works with BRC accredited businesses that are audited by NSF-CMi.
BaxterStorey said there is currently no evidence to suggest any of its suppliers were unwittingly passing off horse meat as beef and added that suppliers had been instructed to suspend the availability of a small amount of chilled and processed beef products as a precautionary measure.
CH&Co said it re-examined its "robust" supply chain controls and found "no cause for concern", emphasising that all fresh beef products used in its restaurants are from a traceable source and are supplied by butchers who are accredited to BRC Food Safety Standards.
Elior said that from the written assurances it has requested and received so far, there is no evidence that indicates any of its suppliers are implicated in the reported incidents to date. The company has also requested that samples are taken in line with the Food Standards Agency requirements as further reassurance.
Lindley Group reported that its food safety supplier assessments are managed by STS is collating evidence of authenticity tests provided by the caterer's meat product suppliers and that no issues have arisen at this stage.
Sodexo said that its review has not identified any products containing horsemeat within its catering supply chain and it is not associated with any of the organisations referred to in recent media reports.