The return of summer holidays abroad is at risk of being delayed by the cyberattack that has crippled the health service for the last 10 days.
The HSE and the Department of Health are centrally involved in developing new IT infrastructure for introducing vaccine passports for international travel.
However, the computer systems underpinning the entire health service are down after an attack by international cyber criminals.
It is feared in Government that this will lead to delays in developing the systems needed to roll out vaccine passports.
Everyone wants foreign travel to return but the HSE and the Department of Health are on their knees and there is no EU system we can just sign up to for the Green Certs. We are starting from scratch on this, a senior Government source said.
It comes as pressure mounts on the Government from the tourism and aviation sector to outline a clear path for the return of international travel.
The Irish Air Line Pilots Association (IALPA) staged a protest outside the Dáil calling for vaccine passports to be introduced from July 1, which is the earliest date they can be used for travel between EU member states.
Cabinet ministers are also pushing to have travel restrictions lifted to kickstart the tourism and aviation industries.
The National Public Health Emergency Team (Nphet) is due to make recommendations on when travel restrictions can be eased on Thursday.
There is concern among ministers that Chief Medical Officer Tony Holohans team will take a more cautious approach than they want.
Tánaiste Leo Varadkar has said he does not expect foreign travel to return until August at the earliest, while Taoiseach Micheál Martin has committed to announcing an aviation plan this week.
Yesterday, the Tánaistes spokesperson said he supported the return of international travel through the digital green certificate plan as soon as it is safe to do so.
We do not yet know when the HSE and Department of Health will be ready to do this logistically, the spokesperson said.
The Government will make a decision on how to apply the Green Certificates in an Irish context on Friday.
Hopefully, this will give the aviation and travel industry a roadmap to follow.
Meanwhile, Tourism Minister Catherine Martin called for restrictions on international travel to be lifted as soon as possible after vaccination passports are introduced across the EU.
Ms Martin said she would be urging Cabinet colleagues to move speedily to allow people to fly in and out of the country once the new digital green certificates were implemented for airline passengers.
Id be advocating for it to be as soon as possible and that will be my voice with my Cabinet colleagues.
But of course at all times we have to be guided by public health advice, Ms Martin added.
Housing Minister Darragh OBrien also said he would be pushing for restrictions on travel to be lifted as a priority.
I have been raising this at every Cabinet meeting and it should not be overlooked that travel, especially through Dublin Airport, is a colossal economic driver for this country, Mr OBrien told the Irish Independent.
We agreed to the green certificates and we should look to implement them as a matter of priority.