The proposal, submitted by Jules Maaten of the rightist Dutch VVD party, was passed by a 571-38 vote.
Maaten described the proposal as an "unusual but effective way" to promote freedom of expression on the Internet.
If adopted, Maaten's proposal would require the European Union to classify any Internet censorship as a barrier to trade and would require that the issue be raised in any trade negotiations. Economic sanctions and trade restrictions have been used as means of getting countries to change their policies, but Maaten's initiative is one of the first to tie trade to Internet censorship.
The measure will go to the European Council, which can adopt the proposal as passed by the European Parliament or send it back with amendments.
The initiative targets countries that have enacted heavy restrictions on what their citizens can do and see online.
China, on the list for its "great firewall," is well known for blocking certain phrases and websites from view within its borders. The country has turned its attention to RSS feeds and "encourages" bloggers to register with the government, ARS Technica reported.
"The 'great Chinese firewall' should be seen as an international trade barrier," Maaten said, according to Livre. "In addition to American companies like Google, Yahoo! and Microsoft, European Internet companies like Wanadoo, Telecom Italia and France Telecom have to unwillingly censor their services in authoritarian states."
The U.S. companies Maaten named have been criticized for their willingness to go along with the Chinese government's censorship requirements.
In early 2006, executives from those companies were taken before Congress to answer questions about their business practices in China, and Yahoo! has apologized for withholding information from congressional investigators looking into the company's disclosure of dissident emails.
Amnesty International also has been critical of Google, Microsoft and Yahoo!'s dealings in China.