The picnic in the park event at Adur Recreation Ground will feature films on the big screen, a silent disco, pre-recorded music, live comedy and some short live music sets.
Guests will be allocated their own picnic pitch for up to six guests which, once seated, they will not be able to leave, to ensure social distancing can be maintained.
The organisers said the event had been closely planned with the local council, health and safety consultants and police, and was in line with all guidance and legislation regarding COVID-19.
But a local councillor has raised safety concerns, particularly about the impact of people travelling to and from the event.
Councillor Joss Loader said: “I fully understand that people are keen to adjust to the new normal and to enjoy outdoor events.
“But I’m concerned that there is little time to make sure all the necessary safety and risk assessments are in place.
“Adur Rec is flanked by narrow pavements to the south and it will be difficult to ensure that people access and exit the site in line with social distancing guidelines
“On the basis that we are still limiting the number of people who can attend weddings and funerals, the approach seems inconsistent?
“We’ve also seen parking bays removed on the nearby High Street to ensure that people aren’t walking too close together.
“This has proved hugely unpopular with many traders.
“There are also concerns about late-night drinking, music and general disturbance on four consecutive nights.”
The maximum number of guests that could be on site at one time is 480, organisers have confirmed.
However, as a higher number of the two-person pitches are expected to sell, they said the number is far more likely to be 300 maximum.
An application has been lodged for a temporary premises license from the council for the event.
Permission to serve alcohol is being sought from 1pm to 11.30pm on the Friday, 10.45am to 11pm on the Saturday and Sunday, and 12.15pm until 11pm on the Monday.
Find out more about about the event on the website here.