The DUP has said it will await details around proposals for mandatory vaccine passports in the North before deciding whether to support the move.
The party said the best way to maximise vaccine uptake was with encouragement rather than compulsion and said it would be uncomfortable with a situation where access to services was based on vaccination status.
However, a DUP spokesman said the party would always act in the interest of protecting the North's health service.
Health Minister Robin Swann has called for a phased introduction of mandatory passports and his proposals are set to be discussed at Stormont on Wednesday. It is not yet clear whether a final decision will be taken at that meeting.
The Executive currently recommends that nightclubs and other entertainment venues use Covid status checks on entry, but it has stopped short of making it a legal requirement.
The issue has sharply divided the five-party coalition in Belfast, with the SDLP and Alliance having been calling for weeks for a mandatory certification system as a way to make venues safer and drive up vaccination uptake rates.
The two main parties in the Executive – the DUP and Sinn Féin – had resisted those calls for compulsory passports, instead expressing a preference for a “partnership approach” with the hospitality industry.
The intervention by Ulster Unionist Party (UUP) minister Mr Swann has shifted the dynamic within the Executive.
Sinn Féin deputy First Minister Michelle O’Neill responded to his announcement on Monday by making clear her party would follow the advice of health officials on the matter.
The position of the DUP could therefore prove pivotal in determining whether the system will be introduced.
If the DUP opposed the move it could potentially block the proposal by deploying a cross-community voting mechanism.
If the party opposed it but did not deploy that mechanism, the support of the other four parties would be enough to see mandatory passports introduced.
Some prominent DUP members, including current Agriculture Minister Edwin Poots and former Economy Minister Paul Frew, have voiced opposition to the proposal. However, a party spokesman said a final decision had not been taken.
“We need to see the detail of the Health Minister’s proposals and how this would be managed. We will then come to a decision,” he said.
“We feel the best way to maximise vaccine take-up is to encourage rather than force.
“Proof of vaccination or a negative test has been used for a large number of events such as Balmoral Show.
“We don’t want to be in a situation where people’s access to services is based solely on vaccination. That sits uncomfortably with us, but we must always act in the interest of protecting our health service.
“In many cases, people without a vaccination are more seriously impacted by Covid-19 and therefore require hospital treatment.”
Mr Swann’s proposal comes amid escalating pressures on the North's beleaguered health system.
Covid-19 transmission rates have also surged in recent weeks, particularly among young people.
Mr Swann said he wanted ministers to discuss the timing of the move and what settings it should be initially applied to.
