Dismal prices for hoggets - Tuesday's daily average fell to 103.64p per kilo liveweight - have prompted an angry response from the National Sheep Association.

The NSA is dismayed at the latest figures from the English Beef and Lamb Executive showing a significant increase in the retail shelf space occupied by overseas products. The figures for March show a 9% increase year-on-year, with the result that more than 55% of fresh and frozen lamb sold through retailers in that month was imported.

The dire situation for hogg finishers has various causes. Hoggs did not finish particularly well this winter as a result of the exceptionally wet weather, and that delayed slaughtering. The oversupply situation is compounded by finishers holding on to hoggs in the hope that prices might improve. That has led to increased supplies to the market compared with last year, with some auction markets reporting record throughputs at recent sales.

Despite the increased domestic supplies, the main reason prices are depressed has been the increase in imports from New Zealand as a result of the weak dollar in relation to the strength of sterling.

New Zealand exports 92% of its lamb production. Although there are voluntary import restraints into the European Union, New Zealand has increased its exports of chilled lamb to the UK in the first quarter of this year, partly in response to increased demand from UK supermarkets that prefer the product at this time of year, but mainly as a result of the strength of the pound.

Peter Morris, NSA chief executive, said: "The publication of these figures gives the sheep industry every right to feel badly let down by the retail sector. There is plenty of good quality UK lamb available, yet our so-called partners in the supply chain choose not to support the home-grown product and import extra lamb at the drop of a hat.

"All the hype we hear about corporate responsibility, a desire to support the countryside and buy British whenever possible seems to count for little in reality. The prices that sheep farmers are receiving for lambs are absolutely diabolical."