The moves comes as the number of construction workers at the site who have been diagnosed with the coronavirus rose to 85, up 15 on yesterday.

It is expected the testing will be available from early next week to the up to 5,000 design, engineering and building contractors working on the multi-billion-euro facility and will be offered weekly.

In the meantime, the HSE is carrying out sweep testing to try to identify anyone who has contracted the virus as part of the current outbreak.

Construction unions, SIPTU, Connect and BATU, which represent workers on the site, are due to meet with the project’s main employers and the Construction Industry Federation on Tuesday.

They will be discussing how the outbreak came about and what can be done to prevent it occurring again.

Earlier, the trade union Unite which also represents construction workers, said there is an urgent need for a rigorous Covid-19 testing regime on construction sites.

It said it first called for testing in May of last year and in March wrote to Intel’s project management companies Exyte and DPS Engineering pointing out that rigorous testing would not only increase confidence among those working on sites but also minimise the risk of business interruption.

“The Intel outbreak must act as a wake-up call for the sector as a whole,” said Unite Regional Officer Tom Fitzgerald.

“In addition to a renewed focus on basic hygiene facilities, there is now an urgent need for a regular on-site testing regime conforming to best practice.”

“As the economy continues opening up, we must take all necessary measures to protect the health of construction workers and their communities, and regular Covid-19 testing is fundamental to that.”

The construction industry is hoping to get a green light from the Government next week to reopen the remaining parts of the sector still shuttered by Covid-19 restrictions.

Minister of State at the Department of Enterprise, Robert Troy, indicated during an ISME webinar today that it is likely permission to resume in early May will be given.

Mr Troy was non-committal on the question of whether the Government would be prepared to subsidise the cost of antigen testing in some sectors, saying he thinks that people and businesses are aware that while antigen testing is not the answer, it can be part of a suite of measures that can be used.