The travellers on Tarring Park in Worthing have been officially asked to leave, according to West Sussex County Council.
The group arrived on Tuesday (July 3) and initial pictures showed at least four caravans, which has been confirmed by the council.
A spokesman said: “There are four caravans at Tarring Park and notice has been served requiring them to vacate the land.
“If they fail to do so we will commence court proceedings.
“Sussex Police are aware and together we will continue to monitor the site.”
The news follows a statement from Worthing Borough Council on Wednesday (July 4) saying they had asked the police to exercise their powers under Section 62a of the Criminal Justice and Public Order Act to move the group to the Gypsy and Travellers Transit Site in Westhampnett, Chichester.
Section 62a gives the police power to ‘remove trespassers’ if an ‘alternative site is available’.