The Irish Government is 100% behind bringing Northern Ireland's corporation tax to the Republic's low level.
Finance Minister Michael Noonan has told a lunch for business leaders in Belfast that the controversial levy was one of the biggest factors in attracting foreign investment.
And the minister said tourism was one of the sectors where cross border collaboration benefits everyone.
"Our IDA often refers to the three Ts when marketing Ireland as a destination for foreign multinational - talent, track record and tax," Mr Noonan said.
"I know that the focus for many here is on the third T - corporation tax. Like in the tourism sector, I am of the view that by working together we can deliver real benefit. That is why we fully support your application for a 12.5% corporate tax rate."
He said foreign direct investment had been a "major advantage" to Ireland during the economic crisis.
Ireland has come under repeated fire from other European countries, claiming its relatively low rate of 12.5% corporation tax was giving it an unfair advantage in luring global multinationals to Dublin.
Firms like Yahoo, Twitter and Facebook have their European headquarters in the Irish capital, leaving the north struggling to compete with its much higher corporation tax of 23%.
Mr Noonan, who was guest at the CBI Northern Ireland annual business lunch, is examining whether to raise the special 9% VAT rate for the hospitality and tourism sectors in next month's budget.
He is on record as saying the low rate created 15,000 jobs in Ireland since it was introduced last year and a strong lobby group is resisting pressure for it to return to 13.5%.
Mr Noonan praised Northern Ireland's economic development agency Invest NI for its efforts.
"Our record of foreign direct investment has been a major advantage to Ireland during the economic crisis. The sector has remained a strong employer throughout," Mr Noonan said.
"I would like to acknowledge the work of Invest Northern Ireland, which is putting Northern Ireland on the global stage for foreign direct investment."