Warwickshire County Council leader, Conservative Izzi Seccombe, has held discussions with the West Midlands mayor over joining WMCA
A row has erupted after it emerged Warwickshire is taking steps towards becoming a full member of the West Midlands Combined Authority (WMCA).
The county council has published a report saying it will explore the option of joining.
The BBC understands discussions have already taken place between council leader Izzi Seccombe and West Midlands Mayor Andy Street.
A spokesperson for the WMCA said no formal approach had been made.
The authority is a currently a group of seven councils in the West Midlands.
It is granted money and power by central government to make decisions on issues like transport and the economy.
Warwickshire has been a non-constituent member of the authority since it was established in 2016, meaning it has some influence but does not get a say in all decisions.
Residents in the county do not currently vote on who becomes the region's mayor.
That election process is at the heart of the row, with Labour accusing the Conservative-controlled council of trying to strengthen Andy Street's position ahead of 2024's mayoral election.
The Labour leader of Coventry City Council, councillor George Duggins, told the BBC: "It's becoming clearer that Andy Street will not win that election and he needs to effectively increase the number of voters who he thinks might be favourable to him."
As it stands, leaders of the member local authorities would get a vote on whether Warwickshire could join, and Mr Duggins made it clear he would veto the deal.
There are currently four Labour leaders on the board, and three Conservatives.
But new legislation, the Levelling Up Bill, due to become law this year, could take the decision out of their hands and give the mayor and Levelling Up Secretary Michael Gove the final say.
Mr Duggins said that could spell the end of the WMCA if it was used to allow Warwickshire to join.
"If Mr Gove is really suggesting ripping up the constitution of the combined authority, he's potentially ripping up the combined authority," he added.
Asked if he would take Coventry out of the combined authority over the row, he said: "I'm not saying that at this moment in time. But I think there will be conversations around that and, already, some constituent members are talking in those terms."
In the report, Warwickshire's officials said if the authority was a constituent member there could be "significant benefits" from existing WMCA deals and it could get more from devolution deals with the government.
They admit some issues would be delegated to the WMCA and they would have to pay more as an annual fee but add the move could further boost economic growth in the county.
The WMCA was not actively looking to expand but was aware of the report and would monitor conversations in Warwickshire, the spokesperson for the authority added.
"If a formal approach is made, we will ensure it is considered carefully and through the correct processes," they added.
Mr Street has been approached for comment.