Proposals to merge two councils in a bid to save millions of pounds have been criticised.
Liberal Democrats are calling for a review into combining North Tyneside and Newcastle councils into one.
They estimate that savings in management salaries alone could be worth more than £4m a year – which could then be used on frontline services.
Coun Anita Lower, Liberal Democrat group leader on Newcastle City Council, and Jack Mowatt, chair of North Tyneside Liberal Democrats, said: “At a time when frontline council services are under such pressure, radical solutions are needed.
“Here we have neighbouring councils with so many things in common doing exactly the same things with two of everything and everyone.
“Creating one combined council will make a lot of sense to many people.
“We are calling for a joint review group to be set up between the two councils, including representatives of their scrutiny functions and with external, possibly business, representation to ensure independence and rigour.
“We also think it essential for the public to be consulted.
“Of course it would take some time to realise all the savings, but we now know the financial settlement for local government until 2020, so this is exactly the right time to look at the practicalities and, if feasible, to develop a plan to work towards amalgamation over the coming years.”
They added there was already plenty of precedents around the country, with several district councils coming together.
Investigations could also include the scope for shared use of land and buildings, and the sale of surplus buildings.
The LibDem group also believes having one authority representing nearly 500,000 people would give it a bigger voice nationally and a higher rank among the core cities, putting it ahead of the likes of Bristol, Manchester or Liverpool.
The added: “Also, there has been real difficulty in making much progress on the shared services agenda between councils as no-one wants to give up their empires.
“This would help unlock it, at least for these two neighbouring authorities.
“However, none of this need stop other cross-authority partnerships or collaborations such as the development of the North East Combined Authority or the continuation of the Newcastle Gateshead Initiative. We need a pragmatic approach, with functions provided at the most logical and efficient level.
“That said, there seems to us to be more of a shared civic feel, both historic and present, for the urban area north of the Tyne.
“It would be good to test this as well as the logistics and financial savings of our proposal.”
North Tyneside Council declined to comment.
But Coun Nick Forbes, leader of Newcastle City Council, said the proposal would be an attack on the history of Newcastle while people in both areas were proud of their home’s identity.