Taxi driver unions are to oppose plans to create a vast 20mph area.
Brighton and Hove City Council’s transport committee signed off on plans to introduce the restrictions on more than 500 streets between Sackville Road, Hove, in the west and Freshfield Road, Brighton, in the east.
Only Sackville Road, Old Shoreham Road and the A259 seafront road will be immune from the new limits, which will come in from April.
But the GMB union, which represents about 1,800 taxi drivers in the city, is unhappy it was not consulted after the proposal was unveiled earlier this year.
Representatives have told council chiefs the union will oppose the traffic order when it is advertised in the coming weeks.
They added it will also seek legal advice to see if the local authority had complied with its lawful responsibility to consult.
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