It's expected Cabinet Ministers will agree to sign up to a minimum 15% Corporation Tax rate at a meeting this evening.
Finance Minister Paschal Donohoe will present the revised text of an OECD agreement for a global minimum rate.
Long held as a key part of attracting foreign direct investment to Ireland, it's expected Ministers will spell the end for the country's 12.5% corporation tax rate this evening.
OECD countries are attempting to agree a global minimum rate of 15%, and other changes that would impact where big companies pay most of their tax.
The removal of the phrase 'at least 15%' has been key to Ireland signing up, and Department of Finance sources said last night most of the issues the Government had are bedded down.
It's hoped a final deal can be reached by the 140 countries involved in these talks on Friday, with Ireland one of the last hold-outs.
However, work on issues raised by other countries was continuing late last night.
Finance Minister Paschal Donohoe will bring proposals to Cabinet at 4 o'clock, with a press conference due after.
He's previously said the changes in this deal could see Ireland lose more than €2 billion a year in Corporate Tax take, which would be equivalent to a fifth of the State's annual corporation tax receipts.