The bank holiday Monday is when the main procession takes place for Jack in the Green and the climax of the weekend.
Next year’s early May bank holiday will be moved back by four days for the whole of the UK to coincide with the 75th anniversary of VE Day.
May Day is traditionally held on a Monday but will be put back to Friday 8 May 2020.
VE Day, or Victory in Europe Day, marks the day towards the end of World War Two when fighting against Nazi Germany came to an end in Europe.
Keith Leech, the man who revived the Jack in the Green Festival in Hastings more than 30 years ago, said: “This has come out of nowhere. We have already started organising next year’s Jack in the Green and booked bands for the event. Now we get this with less than a year’s notice. It will cause problems for us.”
There has been a flurry of social media posts from those involved in Jack in the Green over the weekend but no decision has yet to be reached as to what will happen over the weekend.
There have been calls locally for Hastings MP Amber Rudd to intervene and make the case for keeping the Monday May bank holiday as well.
One poster commented: “If we can have an extra bank holiday for a royal wedding then why not for this? They could still have a bank holiday for VE Day and keep the Monday bank holiday as well.”
The change will also affect the May Day Run, which sees thousands of motorcyclists coming to town.
Both events bring thousands of people to the area and help to boost the local economy.
There are concerns that if Jack in the Green takes place over the same weekend as VE Day celebrations in Hastings, there will be a clash.