Industry calls for a supermarket ombudsman have been strengthened after 80% of shoppers said they wanted a watchdog appointed to check suppliers were treated fairly.

A survey of more than 2000 people found the majority of consumers wanted supermarkets monitored and punished if they abused their relationships with suppliers.

More than 80% of people said supermarket behaviour such as paying suppliers less than agreed sums was unacceptable, the poll by YouGov found.

About 60% would consider changing where they shopped if they found out their regular supermarket carried out such practices, while 78% did not realise there was not already a grocery ombudsman in place.

Carried out on behalf of the Cross Cutting Group, an alliance including the NFU, CLA and NFUS, the poll comes as research by Cardiff Business School found an ombudsman would result in more consumer choice, better products and lower prices for agricultural products.

Professor Roger Clarke, who led the study, said the cost of introducing a supermarket-funded ombudsman would be very small compared to the benefits it would bring customers and retailers.

NFU president Peter Kendall said the poll and research came at a vital time, particularly as the Competition Commission was expected to launch plans for a supermarket watchdog in the next few weeks.

“The big retailers are currently lobbying government saying an ombudsman wouldn’t benefit consumers, but the report shows that is untrue,” Mr Kendall said.

“We need to be clear an ombudsman would not push prices up and there’s no need for it to be bureaucratic and expensive.

“If we don’t have one it could put the cost of food up in the longer term.”

West Country MP Andrew George said supermarkets had “nothing to fear and everything to gain” from the creation of an ombudsman.

“Customers would feel more reassured and the good public relations from having the endorsement of an independent regulator would benefit supermarkets which uphold high standards of trading with suppliers,” he said.