Travellers are today setting up camp at Preston Park.
Caravans started to appear last night, and eight are reportedly now at the north end of the park, near the velodrome.
It is not known if these are the same travellers who twice tried to get into Carden Park yesterday but were stopped by residents blocking their way.
One Brighton resident, who described himself as a frustrated dog walker, tweeted Brighton and Hove City Council and Sussex Police saying: “We have travellers in Preston Park AGAIN!!! We do not want this please could you move them on.”
The travellers have set up camp as Brighton-based barefoot charity marathon runner Joe Addison attempts to run for 24 hours round the velodrome from 1pm to raise money for Macmillan Cancer Support.
The run, nearly 105 miles, is the equivalent of four marathons back to back.