Guinness was prepared to drop associations with Ireland and promote itself as an English company during the Falklands crisis, state papers have revealed.
The company may have been forced to cut ties with Irish organisations and functions because of the IRA bombing campaign, public relations chief Edward Guinness told Irish embassy officials in London.
The rebranding plan was prepared on the back of deepening resentment of Ireland and Irish brands in Britain, he said.
"Mr Guinness remarked that an association with Ireland was part of the Guinness image," Paul D Dempsey of the embassy wrote. "He was no longer sure this association with Ireland was helpful.
"They were encountering a lot of resistance to the Irish angle and this could force them to emphasise facts such as that Guinness was an English company which had its base at Park Royal.
"Indeed they had publicity material of this kind ready during the Falklands crisis but had not used it.
"They might also have to cease their association with organisations and functions."
In the meeting on August 18, 1982, Mr Guinness, a descendant of the banking line of the family, refused to accept the views of diplomats that British attitudes to Ireland went through cycles and that opinions would improve.
"In his view the impact of these things was cumulative. The Mountbatten killing had a serious effect. The Falklands crisis and the IRA bombings had added to the damage," he said.
"A fund of goodwill towards Ireland existed. . . This fund was now being depleted."
Mr Guinness, honoured by the Queen with a CVO, was a director of Guinness PLC from 1971 to 1989.