The clash, on Sunday June 23, will see Preston’s famous Caribbean Carnival and the city’s equally popular Windrush Festival go head-to-head for thousands of visitors.
Both will be marking National Windrush Day 24 hours earlier - a celebration of the contribution made by the Windrush Generation to the UK.
Carnival organisers say they have planned their colourful street procession and field day on Moor Park - now in its 45th year - that weekend because of strong links between Preston and the Windrush settlers.
Leaders of the Windrush Festival say their event, two miles away at Preston Cricket Club, has to be as close to Windrush Day as possible.
“There is no animosity between the two groups,” insisted Carnival chair Tracey Harris.
“They are two different types of celebrations . Ours will be a traditional Caribbean celebration, started by our parents and grandparents who came over as part of that Windrush Generation, while theirs is a different approach to it.
"We asked the Windrush Festival if they would put their event on the Saturday, but they couldn’t.”
Adrian Murrell, festival organiser, declined to comment.