The watchdog was proposed last year by the Competition Commission, but the government has yet to confirm that it will impose the control on the multiples after attempts to establish a voluntary scheme failed.
Ensuring a fairer deal for suppliers could see a narrowing of the gap in buying prices between supermarkets and independent retailers, but Shadow environment spokesman Nick Herbert said the current voluntary code of practice governing the relationship between supermarkets and food suppliers was not "worth the paper it is written on" unless properly enforced. "It is not enough to talk loosely about a fair market or the need for better labelling," he said. "We need action, with an ombudsman and legislation to enforce honest labelling if retailers won't act.
"Failure to do so could result in reduced investment by suppliers, lower product quality and less product choice, with potentially higher prices in the long run."
The Tories' announcement follows Labour MP Albert Owen's attempt to force action on the ombudsman with a Private Member's Bill. This is scheduled for a Second Reading debate on March 5.
Association of Convenience Stores chief executive James Lowman welcomed the Tory initiative. He said: "The fundamental point that is often forgotten by the supermarkets is that the CC recommended an ombudsman because it recognised that certain supermarket buying practices were working against the interests of consumers."