Hungary's Prime Minister Viktor Orban says Romania is waging a "political campaign" against the leaders of Romania's large Hungarian minority.
"Under the pretext of constitutionality, legality and the fight against corruption, in reality we have to register a political campaign against Hungarian politicians there" Orban told Hungarian diplomats, on Monday.
The prime minister said Hungary would "have to raise this issue in the proper form."
Last week, Laszlo Tokes, was stripped by a court of a high state honor for suggesting in 2013 that Hungary should take on the "status of protector" for Hungarians in Romania's Transylvania region.
Laszlo Tokes, a Romanian-born Hungarian politician, is a Calvinist minister, his protests had sparked the fall of Romania's communist regime. He currently serves as vice president of European Parliament.
As much as 1.3 million Hungarians live in Romania, mostly on territories that Hungary lost after World War I.