Former taoiseach Bertie Ahern has warned that a directly elected Dublin mayor could prove to be a "dog's dinner".
Mr Ahern addressed the Citizens' Assembly on a directly elected mayor for Dublin.
Its 80 members are tasked with considering how the reformed office should function, before bringing proposals to the Oireachtas.
He said he had previously been in favour of the idea, but having studied its implementation in other cities around the world, he feels it “would lead to friction and be a dog’s dinner of a system”.
He also expressed concerns about celebrities running, who "wouldn't care two damns about the city".
The first directly elected mayor of Dublin could take office as soon as 2024 - Limerick voted in 2019 to make their mayor a directly elected position.
Mr Ahern said any change to the system should simplify local government structures.
"I like systems that are coherent and straightforward, that you know who the boss is, you know what the committee is, and you know what the agenda is. Too much of my political life was spent working about eight organisations trying to find out what the agenda was, and that I don't like.
"I think it's to make it better, and simpler, and that's what we should be trying to do."