Concerns have been raised about the lack of transparency surrounding devolution deal negotiations.
Calls have been made for more information to be shared between those involved so that local authority leaders and officers can learn from each other.
LGC understands the government has put pressure on places to not discuss their negotiations and deals ahead of them being announced.
The Tees Valley, along with the North East, was the latest to secure an agreement over a devolution deal including an elected mayor. The deal includes being given control over an investment fund worth up to £450m over 30 years, as well as European monies, the adult skills budget, and localised business support.
Sue Jeffrey, chair of the shadow Tees Valley Combined Authority, denied she had been sworn to secrecy.
“Nobody ever said ‘You can’t talk about it’,” she told LGC. “It was more the nature of the way the process was done. It wasn’t common practice and people were feeling their way. It was probably just a product of the fact we were at the front of this process but I do think going forward more openness and collective discussion would be more helpful.”
Cllr Jeffrey, who is also leader of Redcar & Cleveland BC, thought the “secrecy and competition” was “unhelpful”.
She said: “I think we should stop being so secretive about everything and we should talk to each other.
“In negotiations we should look at what each other is getting and talk to government collectively about what is being offered so we can come up with a package that’s good for everybody.”
Catherine Staite, director of the Institute of Local Government Studies, told LGC she had concerns about the way deals were being conducted in “isolation” from each other.
She said the private process was “not helpful” to local government and added secrecy might result in “missed opportunities”.
LGC’s analysis of the deals for the North East, Sheffield City Region, and Tees Valley has revealed some subtle differences which could result in a disparity of powers.
Ms Staite said: “It feels like divide and rule, and at the end of this process some people will feel like they have done much better than them for reasons they can’t fathom.
“Because it’s not a transparent process we won’t know why some of those variations have come about.”
Cllr Jeffrey said she would “refuse” to look at any differences between deals negatively.
“We have negotiated what we think is a good starting point for a deal for the Tees Valley and it is what works for us,” she said. “I’m sure every other area will be doing the same.”