SINN Féin says it is developing policy for a 32-county health service to protect medical services affected by Brexit.
Speaking on the second day of the party's 'think-in' event in Co Cavan, TD Louise O'Reilly said they have been examining how to "deepen and develop" current levels of north-south cooperation.
She said that in the context of Brexit, the issue of how health services will be affected is one that keeps coming back.
"We are developing policy on a 32-county health service, which is available for all the citizens on this island," she said.
"Disease does not recognise borders, our health service shouldn't.
"We have been discussing the level of cooperation that exists currently and how we can deepen and develop that."
Meanwhile, former Ulster Unionist leader Reg Empey has called on the British government to return powers for Northern Ireland's health service to Westminster.
Lord Empey urged the government to bring powers back temporarily to Westminster on "humanitarian grounds" to "offset what could be a potential humanitarian crisis in the winter as the health service is totally unable to cope".
The government had an "over-arching responsibility" to the people of Northern Ireland and could not "keep hiding behind the fact that there is no movement between the parties".
Decisions had to be taken, Lord Empey told peers at question time in the Lords.
Northern Ireland has not had a power-sharing government since the Stormont executive fell apart early last year.
For the government, Viscount Younger of Leckie said no option was "off the table" and the government "is prepared to step in to protect the interests of Northern Ireland to ensure the country is stable economically".
He said the government's single most important priority remained to restore an executive at Stormont.
"The people of Northern Ireland deserve this," he added.
Lord Younger said the return of the parties to Stormont remained a "credible and achievable option" and the issues dividing them were not "insurmountable".
For Labour, former secretary of state Lord Murphy of Torfaen said Northern Ireland had been without a government longer than Belgium and it was time for fresh thinking.
He urged the British prime minister to get involved and called for intensive all-party talks and the possible involvement of an independent chairman.
"If we don't do any of these things inevitably we will drift to direct rule, which will be a total and utter disaster," he warned.
Lord Younger said the prime minister remained fully committed to bringing about the restoration of the executive and kept in close touch with what was going on.
