The EU should agree that no final Brexit settlement can be signed off if it's opposed by Ireland, Brian Hayes has warned.
Under the current rules the Brexit deal could be voted through by a qualified majority vote of the European Council - made up of heads of governments.
Unless that changes, Ireland could be "railroaded by other member states into something that is not on our national interests," said Mr Hayes.
The Fine Gael MEP said it would be a disaster for Ireland if a Brexit agreement was concluded over the heads of Irish opposition.
He said it's likely to be a decade before the Brexit process is finally concluded.
He was speaking at the British Irish Chamber of Commerce annual conference in Dublin.
Other speakers at the packed event at Dublin's Clayton Burlington Road Hotel included Health Minister Simon Harris, Deirdre Somers, ceo of the Irish Stock Exchange, Tony Hanway of Virgin Media, Ulster Bank chief economist Simon Barry and former Unilever ceo and patron of the British Irish Chamber of Commerce Niall FitzGerald.
Mr Harris said continuation of cross-Border healthcare arrangements were a priority for Ireland in the coming Brexit talks.
"Patients on the island of Ireland are benefiting from significant developments in cross-Border healthcare activity over the last decade.
"My department is fully playing its part in the interdepartmental group on Brexit with the priority of ensuring continuity of health services, both north and south, and, of course, between Ireland and the UK," he said.
The implications of Brexit for financial services and the food sector were major themes at yesterday's all-day conference, but some of the biggest interest was in the outlook and implications for small and medium sized enterprises.
The focus of financial services was on whether London-based firms will relocate elsewhere in the EU as a result of Brexit, and how much of that investment will come here.
CBRE's Marie Hunt said that there was no question that Dublin has capacity, including office space, to absorb firms moving as a result of Brexit.
Brian Daly, a partner and global head of insurance tax at KPMG, said Irish authorities have taken the view that they are not closed to any business model looking to establish here.
However, he queried whether it might have been better to develop a Brexit approach targeting specific sectors
He warned that some other cities out for Brexit investment were actively running down rivals.
London-based banking lawyer Barney Reynolds, a partner at Shearman & Sterling, warned that some EU members are touting for business on the basis of softer regulation.
"Its very risky for them to do that, but they are doing that," he said.
The chair of investment firm Tilman Brewin Dolphin and former secretary to the UK Treasury, Angela Knight, said there was little scope for so-called regulatory arbitrage inside the EU, but that levels of supervision, and in cases of wrong doing, fines, do vary.
"The arbitrage is not so much the rules, as enforcement of the rules," she said.