An “absolutely ruthless” Tesco was to blame for the collapse earlier this year of the Irish Republic’s only large-scale vegetable co-operative, a parliamentary committee was told in Dublin last week.

According to Colm Warren, a founder member of the now defunct Dublin-Meath Growers (DMG), Tesco had withdrawn its business just two months after the co-op had opened a new €5 million (£4.4m) facility to meet demand from the multiple. As a result, he said, employment at DMG had dropped from 80 staff to just two voluntary workers.

Warren told the all-party committee, which is investigating alleged abuses in the Irish retail trade, that he believed Tesco had rejected DMG because of its support for Irish growers. The multiple had been “absolutely ruthless”, he claimed, and its withdrawal of business had cost DMG more than €600,000 in meeting outstanding obligations to individual growers.

To replace the co-op supplies, Tesco had put in place a system that “beggared belief”, he said, with growers’ produce sent to a distributor in north county Dublin, then taken to Northern Ireland for processing, before being returned to north Dublin for distribution to the Tesco store network.

In response to the accusations, Tesco claimed that DMG had simply lost out to a competitor when the business was put out to tender among six companies, including the co-op. Those who had been supplying DMG were not affected by the new arrangement, a Tesco spokesman said, and the company continued to have a strong relationship with Irish vegetable growers.

On the new replacement system, Tesco insisted that “99 per cent of produce from Irish growers” was processed and distributed within the Republic. The exception was broccoli, which was processed in Northern Ireland because it had the island’s only modern grading machine.

In his evidence to the committee, Warren, a respected figure in Irish horticulture, said his decision to testify was not motivated by revenge. Instead he wanted to get across the message that what had happened to DMG was a symptom of the “disease now affecting the retail sector”. He warned that unless a halt was called to “the predatory activities” of huge retail conglomerates, there would be no development of Irish horticulture.

“How many job losses have already occurred as result of this insatiable rush to get more margins?” he asked. “Who are the losers? The unemployed, the government, the consumer, all of them subsidising the predatory nature of these supermarkets.” The Republic would be lucky, he added, if even a quarter of the remaining 300 commercial growers were still in business within two years.

Horticulture minister Trevor Sargent, who also testified to the committee, said he favoured a statutory code of practice for the sector, plus the appointment of a retail ombudsman, to ensure fair trading and to protect suppliers. Ironically, late last year, he had officially opened the new €5m DMG facility, in the heart of his Dublin north constituency, with Tesco being warmly praised on the occasion for its commitment to the local community.