WARSAW — Hungary’s leadership is under pressure to drop plans to tax Internet use, a move seen as a way to cut off public debate by limiting information not controlled by the rightist government of Prime Minister Viktor Orban.

Tens of thousands of Hungarians gathered in the streets of Budapest this week to protest the plan.

“This is limiting free access to the Internet and information,” said Balazs Gulyas, 27, a former member of the Hungarian Socialist Party who set up a Facebook page last week that inspired the protests. “It is an attempt to create a digital iron curtain around Hungary.”

Mr. Gulyas’s page had attracted more than 230,000 followers by Wednesday afternoon, a day after a large demonstration in the capital, giving it more followers than Hungary’s governing party, Fidesz.

The government denies the tax was devised to inhibit access to information, saying it is an extension of an existing tax on telephones that is being put in effect because a growing share of communication has moved online.