Sinn Fein has said that an opinion poll showing strong support for Irish unity among the under-45s in Northern Ireland shows that the Taoiseach is "worryingly out of touch" with the public mood.
The LucidTalk poll revealed that 43% of 18-24 year olds would definitely vote to leave the UK, compared to 34% who would support remaining. Among 25-44 year olds the gap was even more pronounced with 42% to 29% strongly in favour of Irish unity.
Sinn Fein MP John Finucane said: "The conversation on a new Ireland is under way and it is thriving. Micheal Martin and the Irish Government are worryingly out of touch with the aspirations of the people of this island. The Irish Government cannot stand idly by. They must lead the preparations for a new, united Ireland."
The LucidTalk poll indicated that the NHS would play a key role in deciding a border poll with 35% of people definitely voting for Irish unity, 34% for the Union - but 26% saying they'd likely opt to remain in the UK because of the NHS.
UUP leader Steve Aiken said: "The NHS is quite rightly the source of great national pride within the UK and is the envy of many countries. Its central role has never been more evident than during the Covid pandemic.
"It is perfectly understandable that, in any consideration of the merits of the Union, voters of all persuasions would be extremely reluctant to give up the NHS and exchange it for the system that is in place in the Republic of Ireland."
DUP MP Carla Lockhart said the poll confirmed the importance of "our UK national institutions like the NHS" but said the health service should be strengthened, not at the centre of a "divisive" border poll campaign.
"Northern Ireland benefits hugely from being part of the UK and we have seen that clearly demonstrated through the response to the Covid-19 pandemic. Those who want to remove Northern Ireland from the NHS put their party politics above the wellbeing of the public," she said.
SDLP leader Colum Eastwood said the poll indicated that health was a "key consideration" when considering constitutional change. "That's why the SDLP is undertaking the hard work of exploring what public services in a new Ireland would look like," he said.
"It is a myth that uniting this island means the wholesale privatisation of one of our greatest assets. Our challenge is to conceive a new way of doing things that takes the best of both systems and delivers better health outcomes for our people."
A TUV spokesman said: "Far from the pandemic quickening the drive for Irish unity, it has underscored the fact that we are better off as part of the UK with even the most republican areas applauding the NHS.
"The poll results underscore that, when it comes down to it, the people of Northern Ireland would be too canny to vote for a united Ireland."
Alliance deputy leader Stephen Farry said his party's immediate focus was on Covid and Brexit but "we do nevertheless recognise we are in a fluid situation with multiple conversations around the future of these islands".