Travellers have set up camp on a disused car park in Wakefield city centre.
Several caravans have been towed to the old Balne Lane car park, close to Wakefield Westgate railway station.
Glynn Humphries, Wakefield Council’s service director for environment and Streetscene said: “We attended the site this morning, with the police, to assess the situation.
“As this is private land we immediately contacted the land owner and will be working with them to help resolve the situation as soon as possible.”
Developer Strata Homes received planning permission to build 116 houses at the site in December.
The development will be part of the wider Merchant Gate regeneration masterplan, which has included the new railway station, offices and retail, leisure and food outlets.