The most powerful pro-Israel lobbying organization, AIPAC, is working on drafting legislation that would aim to counter the Boycott, Divestment, Sanctions (BDS) campaign against Israel, two sources familiar with the situation told BuzzFeed News.

The legislation, which has not yet been introduced and has been in the process of being drafted for months, would aim to prevent U.S. companies from participating in the campaign without infringing on Americans' First Amendment rights to political speech. It would also try to make the Transatlantic Trade and Investment Partnership being negotiated between the U.S. and E.U. conditional on whether the E.U. takes action to stop BDS.

"The biggest provisions would be authorizing states and local governments to divest from companies deemed to be participating in BDS; denial of federal contracts to such companies; and threatening the conditioning of the US-EU free trade pact on the EU taking action to stop BDS activities within its jurisdictions," said a Republican foreign policy adviser familiar with the legislation. The bill, the adviser said, originated with a former top aide to Illinois Senator Mark Kirk and has now been "expanded" by AIPAC, which is working with House and Senate offices on the draft.

"This legislation could really change the global dynamic with respect to BDS — in effect, it's a boycott of those who boycott," the adviser said. "It applies the successes we learned from Iran sanctions and applies them to those who seek Israel's political destruction."

The BDS movement, which officially began with a call to action issued by Palestinian civil society leaders in 2004, is modeled on the global economic pressure against South Africa in the 1980s. Its proponents call for a coordinated campaign of boycotts, divestment from Israeli businesses, and sanctions until the occupation of the Palestinian territories ends. The campaign has started to attract the attention of Israeli officials, who have issued dire warnings about it.

Reps. Peter Roskam and Dan Lipinski introduced an anti-BDS bill in February that would bar U.S. universities that receive federal funding from joining boycotts of academic institutions — a measure that would be difficult to square with the First Amendment. The bill never went anywhere.

The legislation drafted by AIPAC could also run into thorny constitutional issues, though the foreign policy adviser familiar with the bill referenced Section 8 of Article 1 of the Constitution, which gives Congress the power to regulate commerce with foreign nations.

"We have the precedent already of the Iran sanctions and other extraterritorial sanctions (e.g. Sudan divestment) where Congress authorized states to divest from foreign companies based on defined activities; or where Congress denied federal contracts to foreign companies based on defined activities," the adviser said. "The Constitutional issue arises when states act on their own without Congressional authorization, thereby interfering with international commerce and foreign policy. On top of that, you have the precedents from the 1970s vis a vis the Arab League Boycott laws -- and those targeted US persons, not foreign ones as is the case here."

A spokesman for AIPAC didn't immediately return a request for comment.