Speaking at the National Farmers Union conference in Birmingham, Tesco CEO Philip Clarke said that in recent years the supermarket chain has stepped up its partnerships with farmers through initiatives such as the Sustainable Dairy Group.

And in the autumn of last year the company stepped up the programme offering direct contracts to farmers to supply Aberdeen Angus beef and fresh pork.

"These direct contracts are overseen by a committee of farmers with the express aim to develop a new spirit of partnership and to offer them the certainty of a fair deal financially," he said.

"We have invested £25 million in this scheme which means we can now pay beef farmers an above market price for their meat and offer pork farmers a cost that is directly linked to the price of animal feed - a major concern, and worry, for many of you and therefore for us too."

He said that all Tesco beef, fresh, frozen and in ready meals is already sourced in the British Isles.

However, Mr Clarke added that in the wakes of the controversy over the discovery of horse meat in some beef products the store is endeavour to source its products from the UK.

"Today I am announcing a sincere commitment to source more of our meat closer to home.

"Where it is reasonable to do so, we will source from British producers. And I invite the NFU and the wider industry to work with us to increase UK capacity for the production of meat and poultry.

"As a first step, I am announcing that from July, all of our fresh chicken must come from UK farms. No exceptions. We will also move over time to ensure that all the chicken in all of our products - fresh or frozen - is from the British Isles.

"These commitments represent a genuine shift in how Tesco sources the products we sell. But we cannot do this without you."

Mr Clarke said that the company is also working with members of the supply chain to achieve greater transparency and to assure the highest standards of production.

And he added that the store is to carry out a "root and branch" review of its supply chain operations.

He told farmers at the NFU conference that the store will be offering two year contracts to farmers and will also be appointing an independent committee to oversee the company's supply chain operations and its relationship with customers and farmers.

The company is also appointing an agricultural director to handle farming issues and contracts.