Gypsy and Traveller camp must leave Newbold Comyn after setting up on Friday and attracting complaints of noise, bad behaviour and disruption.
The group set up unlawfully behind the football pitches in the public open space on Friday when they were issued with noticed from Warwick District Council and Warwickshire Police to leave the site within 24 hours.
But despite warnings, the group was still in place at the Leamington park on Monday morning.
As a result the weekly Saturday Parkrun course was diverted to avoid the area and complaints flooded in over the weekend of noise, disruption and bad behaviour.
One resident and park user complained of cars being raced around the fields late at night, while another contacted the council over noise.
On Monday a spokesperson for the district council said: “We received information on Friday and officers, along with police officers, attended the site to issue notices to leave.
“These noticed were not adhered to within 24 hours and we met with the families on site who assured us they would leave the land after the horse fair in Kenilworth.
“This is not the case and as they remain on Newbold Comyn we have involved our solicitors and legal action will be taken.”
She said that while there is no immediate time restrain on the current action to leave, if families do not comply, a court date will be issued.
Similar legal action was threatened in April when Travellers parked their caravans in the council-owned Newbold Comyn car park.
Around eight families moved outside the Newbold Comyn Arms in a similar unauthorised camp.
The district council is still compiling preferred sites for authorised land for Gypsies and Travellers.