The heat has been turned up on the trademark 'beef' between Supermacs and McDonalds. Supermacs has asked the EU regulator to cancel the use of 'Big Mac' and other trademarks registered by McDonald's.
It's the first substantial move made by the Irish fast food chain after suffering a blow in the international trademark war with the multi national company.
Supermacs has accused McDonald's of trademark bullying by registering names like McJob, McChoice and McInternet and storing them away to damage future competitors.
The names "are simply stored away in order to pulverise some future competitor just as this corporate giant has already tried with Supermac's," Pat McDonagh said in a statement.
The Supermacs Founder also said that McDonald's has trademarked "SnackBox" - which is one of Supermac's most popular products.
Last year, the EU ruled that Supermacs could continue to use its brand name, but couldn't sell fast food like burgers and chicken nuggets.
That decision followed a complaint filed by McDonalds, which claimed customers could be confused by the items being offered by the two rivals.