Ireland's "attractive" 12.5% corporation tax rate could be used to help fund Northern Ireland in the context of reunification, Fianna Fáil's Jim O'Callaghan said.
He also called for the European Union to help finance the process during a 10 to 15 year transition period in the event of a border poll voting for unity.
The Dublin TD made the remarks in a presentation at Cambridge University this evening.
He said: "Just as the potential of the south was unlocked by attracting high-quality foreign direct investment, so too could that of a new united Ireland.
"It is vital for the whole island that we lock in the prosperity that leading multi-national corporations and others have brought to the island to date."
Mr O'Callaghan said Northern Ireland should not be "doomed to forever" to be a relatively poor region of a wealthy country, perpetually subsidised by taxpayers in wealthier parts of Great Britain.
He said: "Harnessing the strength of the whole island would make the six counties a more prosperous region of prosperous country."
The Dublin TD predicted a border poll before 2030.
He said a poll was "likely within the 2020s" but warned unless there was preparatory work there was a danger people in the Republic could reject reunification.
He said Irish unity is a "realistic prospect" and described it as his cherished aim.
However, he accepted that unionism had a different view and said that should be respected.
He said people needed to challenge themselves to look at things from the other perspective.