WASHINGTON — Canada’s ambassador to the United States has issued a stern warning to the most powerful congressional leaders on Capitol Hill over a protectionist piece of legislation that "will have a disproportionally negative impact on intertwined U.S.-Canada supply chains and on jobs in both our countries."

The Canadian Press is reporting that ambassador and former Manitoba Premier Gary Doer sent a letter to Nancy Pelosi, speaker of the House of Representatives, and Harry Reid, Senate majority leader, in which he said the Foreign Manufacturers Legal Accountability Act violates World Trade Organization obligations and NAFTA.

"As Congress considers this legislation, we trust that any legislation that moves forward would respect United States’ international trade obligations," he wrote.

The act — an extension of the protectionist "Buy American" provisions advocated by the Democratic Congress and inserted into President Obama’s stimulus package — would ban imports from companies that don’t have an American agent with a U.S. address.

Aimed at ensuring that foreign manufacturers of defective protects can be served with legal papers, the proposed legislation is the result of the toxic Chinese drywall fiasco of 2006.

Consequently, it’s unclear just how far-reaching the implications are for Canadian exporters, even though they’re not the target of the legislation.

It could face a House vote in the next few weeks.

"In our view, it will adversely interfere with the flow of trade across the border by adding yet another logistical and administrative requirement," Doer wrote. "This would be especially unfortunate in light of our ongoing joint efforts to restore our economies."

The European Union is also up in arms about the law, saying it will be costly and prohibitive for small businesses.