A line of trucks more than 12 miles long has developed at the Ukraine-Poland's eastern border, because of a trade dispute that's putting new strain on Polish-Ukrainian relations.

According to BBC News, at Dorohusk and other key crossing points, Polish truck drivers now block the road with their cabs in both directions, choking the flow of traffic.

Ukraine's ambassador to Poland has called the trucking firms’ protest a "stab in the back" from a country that has been a close ally ever since Russia launched its full-scale invasion. But Polish truckers said they were forced into this extreme step to protect their livelihoods after the EU lifted all entry restrictions on Ukrainian carriers. 

Polish firms say the vast majority of trade has been taken by Ukrainians since the passes were abolished by Brussels.

The protest organizers have permission to protest until January and official negotiations have made no progress yet.