European Minister Dara Murphy has said Ireland would be the "most economically disadvantaged" country if Britain was to leave the European Union.
Speaking at Fine Gael's ard fheis, the minister said Ireland's focus at the moment was on the four issues that Britain wants negotiated with the EU, in order to avoid a Brexit.
These will be hammered out at a EU council meeting next month, he said.
Britain's concerns about competitiveness, red tape, migration and opt-out options in union matters will be the focus of discussions.
Motions debated at the session on Brexit warned of the consequences of Britain leaving the union for Irish jobs and trade.
This could affect the €1bn in trade and services that crosses over the Irish sea weekly as well as the 200,000 Irish jobs linked to Britain, delegates heard.
But Minister Murphy warned that a Brexit would harm Ireland's economy more than any other country, beside Britain itself.
The Irish government, he said, was aware any deal for Britain "should not disadvantage Ireland", he said.
Mr Murphy though said he could not see how any of the topics being debated would see Britain "having a competitive advantage" over Ireland.
British ambassador Dominick Chilcott said the Irish dimension of the debate around Brexit was now coming into focus in the British political system.
There were 1.3m Irish voters in the North, several hundred thousand living in Britain as well as another four to five million of Irish descent who would have a say in the Brexit referendum, the ambassador told the ard fheis.