A bipartisan group of lawmakers, led by Senators Ben Cardin (D-MD) and Rob Portman (R-OH), is quietly working to criminalize the boycotting of Israel.

The bill, appropriately titled the Israel Anti-Boycott Act, establishes criminal and civil penalties of up to $1 million for American persons and companies who engage in actions “which have the effect of furthering or supporting . . . restrictive trade practices or boycotts fostered or imposed by any international governmental organization against Israel.” While it’s unclear how strictly the act would be enforced, it is clearly a gross infringement on free speech — targeting Americans who choose to exercise their First Amendment rights and engage in an organized boycott.

The Senate measure was conceived after the United Nations Human Rights Council voted in 2016 to create a “blacklist” of companies that do business in Israeli settlements in the West Bank and East Jerusalem. Building on a 1979 law designed to counteract the Arab League’s boycott of Israel, the Cardin-Portman legislation would extend the existing prohibition to cover boycotts against Israel called for by international organizations like the United Nations and the European Union.