BUDAPEST, HUNGARY - Oppression of the opposition by Prime Minister Viktor Orban's government is greater than when Hungary was under Soviet domination, Hungarian-American financier and philanthropist George Soros said Friday.

Soros said in video messages that he had an "unbridgeable conflict of principles" with Orban and if the Budapest-based, Soros-founded Central European University were to be expelled, it would continue operating "in exile" and return after Orban's departure.

Soros, 87, said Orban has created "an anti-democratic system ... a mafia regime where they use their leading positions to keep themselves in power and personally enrich themselves."

"He exploits and oppresses those who are in opposition. In my judgment, the regime now oppresses people more that during the Soviet occupation."

Orban, who opposes migration, especially by Muslims, claims Soros wants to flood Europe with migrants.

A "national consultation" ending Friday included a billboard campaign against Soros, the second this year. It said the "Soros plan" was responsible for mass migration into Europe. Voters were sent questionnaires with claims about Soros' alleged positions on migration which he has refuted or denied.

Soros supports limited migration but says no country should be forced to take anyone in. Orban says Hungary does not want to turn into an "immigrant country" like many in Western Europe. In 2015, Hungary built fences on its southern borders to keep out migrants, many from war-torn Syria.

Orban, who briefly studied at Oxford on a Soros scholarship in the late 1980s, said on state radio Friday that non-governmental organizations funded by Soros are preparing to act as political parties during the campaign before April's parliamentary election to help weaken or oust anti-migration governments like his.

Orban recently asked for Hungary's intelligence services to identify and investigate the "network" of Soros organizations to uncover their extent and influence.

"We are faced not only with a large network but also with a talented man," Orban said. "The Soros-type network and machinery has registered for the elections."

Orban, who will seek his third consecutive four-year term, and fourth overall, will be running against currently weak and divided opposition parties. He has been striving to present Soros and the European leadership in Brussels as his Fidesz party's main rivals in the elections.