Former workers of Natural Dairies have called on the Competition Authority to investigate why the dairy was forced to cease trading last Thursday.

In a protest outside the offices of the Competition Authority yesterday, the workers blamed the closure on anti-competitive practices by other milk suppliers.

In a separate statement, Mr John Molloy, owner and managing director of Natural Dairies, said he was being forced out of business by anti-competitiveness practices geared at fixing the retail price of milk.

He said there was reluctance at a political level to address the issue because of the strength of opposition from the farming community.

The family-owned dairy, which sourced more than 90 per cent of its milk in Northern Ireland, found it could not replace its supplies with milk from the Republic when it had to halt imports because of the outbreak of foot-and-mouth disease.

Attempts to source milk in the Republic of Ireland failed, leading to the closure of the dairy. But workers protesting yesterday said Lakeland Dairies had supplied the company with milk for a number of days before cutting off the supply.

The workers claimed pressure to halt supplies had been brought to bear on Lakeland by elements in the farming community.

Mr Molloy said he had been told unofficially that some of the country's largest dairy processors are behind the move to cut off his milk supply and put him out of business.

The Irish Farmers' Association has rejected the allegations that it is behind moves to put Natural Dairies out of business. Members of the IFA were involved in a picket of the Natural Dairies premises last October when they objected to it supplying raw milk to Dunnes Stores.

Dr John Fingleton, chairman of the Competition Authority, confirmed it was currently investigating allegations of anti-competitive behaviour raised by Natural Dairies.