Tesco has committed to ­review the price it pays its dedicated dairy farmer group after an "exceptional" rise in on-farm costs.

The price Tesco pays its Tesco Sustainable Dairy Group farmers for their milk is usually set bi-annually in April and October after costs have been calculated by independent consultants Promar.

However, because 2010 had been an exceptional year in terms of on-farm costs, Tesco had decided to conduct a "sense check", according to a spokeswoman.

If the review found the farmers needed more money, then Tesco would pay more, but it would not reduce the price they currently received, she added. The January review was exceptional and the system of bi-annual reviews of the TSDG price would not change.

TSDG farmers signed up to Promar's cost tracker currently receive 28.18ppl for their milk. Farmers not signed up get 27.68ppl.