The owners of 17 caravans which are illegally parked near to the West Common in Lincoln have been given 24 hours to vacate.
The travellers arrived on a green between the Lincoln Grandstand and Carholme Golf Course off Saxilby Road on Saturday, April 18.
The City of Lincoln Council, Lincolnshire Police and Lincolnshire County Council have issued a letter to the group, demanding that they leave before legal action is taken against them.
Steve Bird, Assistant Director for Communities and Street Scene at City of Lincoln Council, said: “We are aware 17 caravans arrived on the West Common on Saturday (April 18).
“We have carried out the necessary checks and are continuing to monitor the situation, working with the police and Lincolnshire County Council, in accordance with the Joint Protocol on Unauthorised Encampments in Lincolnshire.
“We have issued a letter today (Monday, April 20) giving the travellers until 2pm tomorrow (Tuesday, April 21) to vacate the site before we seek an Order for Possession from Lincoln County Court.”