Two years ago, these junior creatives came up with a very similar idea to Burger King's joint 'McWhopper' ad

Last week Burger King made headlines after it took out full-page advertisements in two US newspapers, proposing a truce with its rival McDonald's and suggesting they make a hybrid "McWhopper" burger together to help raise awareness for the Peace One Day charity.

Burger King said the stunt was co-created by all its rostered ad and marketing agencies, including Y&R New Zealand, Horizon, Turner Duckworth, Rock Orange, The David Agency, Alison Brod Public Relations, and Code & Theory.

But George Walters and Ewan Harvey, two UK-based junior creatives who currently work at ad agency DLKW Lowe, say they devised a very similar idea in 2013. We first spotted their work over at Agency Spy.

The duo came up with the concept of getting a number of competing brands to come together on Peace One Day's annual September 21 date, which it aims to turn into a global day of ceasefires and non-violence. Alongside the "Big Mac Whopper," the duo suggested "Coca-Pepsi," "Addinike," "WhatsAppBBM," and a Lamborghini/Ferrari hybrid, as you can see on their portfolio.

Walters and Harvey aren't accusing Burger King and its agencies of seeing the work and going on to create the McWhopper ad. They told Business Insider that "ideas can come from anywhere" and the creation of the "McWhopper" campaign doesn't mean that Burger King and its agencies have ever seen their online portfolio or book.

But there's no denying that the two campaigns are very similar - even if it is a coincidence.

Here's the Big Mac Whopper idea Walters and Harvey say they first published to their portfolio and book in 2013.

And here's the Burger King "McWhopper" advert published last week.

Walters and Harvey told Business Insider: "Our Peace One Day idea was a wider concept about bringing many brands together annually for Peace Day. We hope that this can still be the case as this idea could continue to raise awareness for an amazing charity year after year. The stunt from Y&R New Zealand feels like it is just the beginning of something that could be so much bigger and we hope it continues to evolve and grow."

Business Insider has contacted Burger King for comment, and we'll update this article once we hear back.

In a separate incident, McDonald's apologized last month to a pair of freelancers who accused the fast food chain of stealing their idea in a recent marketing campaign.