It is expected that Fianna Fáil will decide to expel former Taoiseach Bertie Ahern from the party when its officer board meets this evening.
The former party leader is examining the findings of the investigation and will give a statement "in due course".
Fianna Fáil Justice Spokesman Dara Calleary said that the report's findings are "stomach-churning".
"This is a very serious day for our party," he stated.
"We will respond accordingly, we will deal with this head-on. We're not going to shy away from this...We will (respond) fairly, and that will begin with the meeting of our officer board this evening."
READ THE FINAL MAHON REPORT HERE