Despite a rejection from McDonald’s, Burger King in the US is hoping to go ahead with its mammoth collaboration burger for Peace Day.

When Macca’s flatly refused Burger King’s proposal to create a hybrid McDonald’s/Burger King McWhopper, several other fast food chains hopped on the chance forget about their rivalry, and to get some publicity, offering Burger King options for creations.

In a similar style to how it proposition McDonald’s, Burger King penned an open letter to American chains Denny’s, Wayback Burgers, Krystal, Giraffas and McDonald’s again, offering them to the chance to be involved in its pop-up restaurant apparently already under construction.

Read the letter below.

During the initial excitement of the burger possibility, Burger King really came out on top in the social media buzz, way ahead of Macca’s.

While the jury is still out whether McDonald’s will come to the party, this Burger King tweet suggests the other chains are in on the burger.

.@DennysDiner @GiraffasUSA @Redegiraffas @Krystal @WaybackBurgers proud to partner with you on the #PeaceDayBurger pic.twitter.com/GRgjCCtbFs

— Burger King (@BurgerKing) September 2, 2015