In today's Autumn Statement, the chancellor revealed that talks that concluded last week meant there would be "additional spending power for the executive to support the full implementation of the Stormont House Agreement".
“That opens the door to the devolution of corporation tax - which the parties have now confirmed they wish to set at the rate of 12.5 per cent," he added.
This would put the onus on the Northern Ireland Executive to "play their part and deliver sustainable budgets to allow us to move forward".
Northern Ireland’s block grant will be more than £11bn by 2019-20, while and funding for capital investment in new infrastructure will rise by more than £600m over five years, "ensuring Northern Ireland can invest in its long-term future," Osborne said.
The move will open a can of worms when it comes to the other nations, however.
Plaid Cymru has already tweeted its dismay at the measure, saying "Chancellor confirms Northern Ireland will get corporation tax powers but Wales will not. How can this be justified?"
Chancellor confirms Northern Ireland will get corporation tax powers but Wales will not. How can this be justified? #csr2015— Plaid Cymru (@Plaid_Cymru) November 25, 2015
And of Scotland, Osborne noted that if the electorate had voted for independence "they would have had their own Spending Review this autumn".
But this would have been "catastrophic" given the fall in oil prices. "Thankfully, Scotland remains a strong part of a stronger United Kingdom.