Hull Council is proposing 10 permanent pitches and up to 17 temporary ones next to a long-established site on Bedford Street.
Lib Dem councillors Linda Chambers, Diana Hatcher and Adam Williams say some of the travellers, who have made permanent homes, have raised “the very real potential for serious community cohesion issues” if it goes ahead.
The council’s highways department is also objecting, concerned that building an “unnecessary” extra access onto Mount Pleasant will create delays on the busy route as vehicles turn into the site towing caravans.
Others say the scheme will cost the taxpayer £4m, but not stop the year-round problem of illegal encampment.
Meanwhile Humberside Police has suggested the council should look for alternative more appropriate sites or consider further measures to improve security at the site.
Planners are recommending approval, with the plans sent to the Secretary of State for a final decision because of an outstanding objection from the Environment Agency over flood risk.
A report to councillors next Wednesday says a number of sites have been investigated to use as authorised stopping places for travellers. It adds: “All have met significant opposition from local residents (including the settled traveller community) and their representatives.”
There are no transit pitches or stopping places in the city. Over seven years to 2019 there were 92 illegal stop-offs by travellers to the west of the river Hull, and only 56 to the east, where the proposed site is.