Business leaders have sent a letter to councils in South Yorkshire expressing anger about delays in plans to devolve power to the region.
Local authorities in South Yorkshire and the North Midlands first agreed to a government deal to have an elected mayor for the Sheffield City Region in 2015.
However, Bassetlaw and Chesterfield have withdrawn from the deal and that plan has since been put on hold.
The letter, addressed to 'the Leaders of Barnsley, Doncaster, Rotherham and Sheffield Councils', says they "are very concerned about reported further delays in bringing to fruition the devolved powers deal for our region."
It argues that there is a risk of losing "significant funding" and "damaging" the region's reputation by delaying the devolution.
Earlier this month, a separate Yorkshire Day agreement saw North Yorkshire and York work with councils in West Yorkshire, East Riding and Hull, Barnsley and Doncaster to sign up to a deal which could bring devolution to the whole region.
However, in the letter, business leaders say the idea of a "pan-Yorkshire deal" should not overtake a South Yorkshire plan.
Barnsley, Doncaster, Rotherham and Sheffield Councils have yet to respond to the letter.