Mr Feargal Quinn of the Superquinn supermarket chain is philosophical when assessing the threat posed by the Tesco invasion. "I am in the business 36 years and I am always worried that someone will take our customers away," he said.

But "customers benefit from competition" and the only danger will be if "the bias in favour of Irish produce isn't understood by the newcomers."

All the main supermarket chains have been preparing for such developments for three years. In 1992 Superquinn was the first company in Europe to introduce a loyalty card, and the Superclub card remained the most sophisticated of the three currently on offer, he said.

Acknowledging the growing move towards convenience foods, the What's For Dinner section was established.

"We are concentrating on freshly-prepared food that is made hot in front of the customers' eyes and will stay hot until they get home," he said.

Superquinn has applied for planning permission for a store in south Bray. He is confident that should Tesco set up in Quarryvale in west Dublin, Superquinn customers in the nearby Lucan store will not stray.

The recent introduction by Dunnes Stores of a loyalty card is seen as a direct response to Tesco and its hugely popular (in the UK) Clubcard. The scheme already has in excess of 150,000 members.

Dunnes plans to open in Eyre Square, Galway, by the end of 1997, and planning permission has been granted to rebuild in Sligo. It is currently rebuilding in Swords.

"There is growth all over the place," said a spokeswoman.

A sizeable investment has been made in technology, and key management appointments have been made in anticipation of Tesco's arrival.

Supervalu/Centra claimed not to be worried. "They are taking over an existing business and we had anticipated their arrival for several years," they said.

"All's fair in the supermarket war, and talk of threats to jobs has just given Tesco a whole load of welcome publicity."

Roches Stores declined to comment on how they would face the Tesco threat.

But an industry source said that the company "had always been small with a rural following. If there is a place for them it would be quite small."

Mr Quinn concluded: "I won't blame Tesco if we do lose customers. If we all continue to satisfy our customer base, that is simply not going to happen."