Plans for a joint Solent authority which could secure £900m in government grants have been agreed after a U-turn by Isle of Wight council bosses.
A meeting on Monday reversed an earlier vote not to proceed with the devolution partnership with Portsmouth and Southampton.
Council leader Jonathan Bacon said the island could still withdraw if the terms of the deal were unfavourable.
Portsmouth leader Donna Jones said she was "delighted" by the news.
She said the authorities would now discuss financial terms with the government, which could lead to an announcement in the chancellor's Autumn Statement on 23 November.
Mr Bacon said a devolution deal was the only way to address the island authority's "perilous financial state", following budget cuts of more than £50m over the last five years.
He said his independent-controlled executive reversed Wednesday's vote by the full council, which has no party majority, in order to keep all options open.
He said councillors would need to vote again after negotiations with the government.
Isle of Wight Conservative MP Andrew Turner had warned the island's needs "could easily be over-ridden" by Southampton and Portsmouth, and the potential £900m regional grant over 30 years was an "estimate", not a "government promise".
Mr Bacon said the government had confirmed the money was "definitely on the table".
Under the deal, the councils would leave the current system of government funding in exchange for keeping business rates of about £210m a year.
The three councils would continue as separate entities and retain their existing powers, but they would also be equal members on a board led by an elected mayor.
- The Isle of Wight, Portsmouth and Southampton councils, which currently control about £1.5bn a year of public spending, would retain most of their existing powers
- Under devolution they would set up a new Solent Combined Authority (SCA), overseen by an elected mayor
- The SCA would receive extra money to spend on projects to boost economic growth, with the aim of increasing business rate income in the future
- The government has indicated the extra grants would be worth £900m over 30 years, although the amount is subject to regular reviews
- The SCA would take over skills funding from government to focus education programmes on local business needs
- It would be an "early adopter" of government plans for all councils to leave the current grant regime in return for retaining an equivalent sum in business rates