Máté Kocsis, the ruling party's group leader, insisted that the opposition Tisza Party had made an alliance with the European People's Party "to harm Hungary".
Máté Kocsis said the international corruption network has bought politicians, journalists, activists and media platforms in Hungary.
The amendment was passed in an extraordinary procedure with 136 votes in favor and 27 against.
Máté Kocsis said that in recent years, "foreign powers and speculators" had been interfering in Hungary’s internal affairs on an increasingly broader scale.
In an interview with Magyar Nemzet, he emphasized the urgent need to expose and eliminate foreign funding networks operating in Hungary, particularly in the wake of the USAID scandal.
Máté Kocsis said Donald Trump's administration had "unmasked the corruption network", showing that money was spent worldwide "to spread extremist, liberal ideology".
Máté Kocsis said a commissioner would be tasked with travelling to the United States to recover all relevant documents and to regularly brief the government on the data that will then be made public.
The Ukrainian state's smear campaign "expressly aims to undermine the international reputation of the head of government and weaken Hungary's ability to enforce its interests," Kocsis said in a Facebook post on Tuesday.
Máté Kocsis noted that DK leader Ferenc Gyurcsany and Tisza head Peter Magyar hardly got along on a personal level, "but clearly this isn't a personal matter".
An early election has not been held since 1990 and another will not be held in future, Máté Kocsis said.
The ruling party will hold a "National Consultation" public survey on "trade neutrality, support for small and medium-sized enterprises, wage increases, employee loans, as well as housing and family support".
Máté Kocsis has called for using all means against any form of incitement of or reference to threats to life.
The current EU leaders have been unable to guarantee peace or prosperity, and there is war and a weakening economy instead, Máté Kocsis said.