Cardiff city deal: Councils locked in for five years
Details of the way ten councils in south east Wales will work together on a £1.2bn investment deal have been published.
If agreed, the Cardiff Capital Region City Deal will see £734m invested in the Metro transport scheme and £495m on other projects.
The councils - expected to contribute a total of £120m - will vote on the agreement over the next few weeks.
They will be "locked in" to the deal for five years before any can quit.
Most of the money will come from the UK and Welsh governments, with the hope that private investment will be attracted too.
Councils' contributions will be based on population, with Cardiff providing 23.7% of the local authority money.
If a council decides it wants to get out of the deal after the five-year lock-in period, it will have to give one year's notice and pay to cover certain costs and liabilities.
A regional cabinet will be created in March to develop potential projects and formulate the business plan.
It will initially spend up to £50m of UK government money.
Rhondda Cynon Taf council leader Andrew Morgan, who chairs the city deal council leaders' group, said it would bring about an "economic and social step-change" in the region.
Some Labour councillors in Cardiff told BBC Wales they were "reassured" the agreement gives councils a way out of the deal if they can't agree on projects.
But Cardiff North Conservative MP Craig Williams has said councils must see the votes as "binding".