IRFU chief executive Philip Browne has written to World Rugby to express concern over the recommendation of South Africa to host the 2023 World Cup ahead of Ireland and France in an evaluation report last week.
In a lengthy correspondence, Browne has outlined what he sees as potential scoring issues in the report under "Stadia", "Security", "Major event hosting experience" and "Financial, commercial and commitments" for South Africa's bid.
Browne queried whether the Commonwealth Games decision to strip their event from Durban in 2022 was taken into consideration and particularly criticised what he perceived as the report's willingness to overlook South Africa's ability to fill stadia for the tournament.
"Full stadia for all matches is critically important to the success of the tournament as a live event and for broadcast around the world," he wrote.
"Whilst certain significant risks were noted in relation to the overall size of match venues in the South African bid, and its ticketing strategy, these do not appear to have been fully reflected in the scoring. There are very clear examples in recent times of starkly empty stadia in South Africa for significant fixtures.
He also promised a follow-up of "a more extensive list of queries with the evaluation report" by the end of today.
The letter was sent to World Rugby counterpart Brett Gosper and copied to World Rugby Council members.
It follows the Irish bid’s team reiteration that they will not throw the towel in on their bid to host the tournament despite seeing two other countries receiving a better recommendation in the report.
Browne asked World Rugby to remind council members that "they may vote for any of the three bids and that all bidders have been judged capable of hosting an excellent Rugby World Cup in 2023."
Voting takes place on 15 November.
The full letter has been disclosed by the Irish Times here.