Just when you thought that everyone was content to let debates about the Anti-Counterfeiting Trade Agreement (ACTA) simmer down, a group of American legal scholars has now submitted an open letter to the United States Senate, challenging the lack of a Congressional approval process for ACTA.

The letter, published Wednesday, argues that Congress needs to review and approve ACTA, and that the Obama Administration lacks the executive authority to ratify the agreement on behalf of the United States without explicit congressional approval. (This is a position that Harold Koh, a legal advisor to the United States Department of State, has previously taken, though Koh argues the authority was granted by 2008's PRO-IP Act). Normally, the United States Constitution delegates authority to ratify treaties to Congress, which can also give that authority to the White House through either an “ex ante” or an “ex post” Congressional-Executive Agreement.

“The reason Congressional approval is important is that it provides the public process so sorely lacking from the negotiation of the agreement itself,” wrote Sean Flynn, an intellectual property lecturer at American University and one of the letter’s organizers, in an e-mail to Ars. “There has not been a single public hearing on the ACTA text and its impact on US law, for example. As the EU, Australian, and other parliaments provide public processes on ACTA for their own citizens, now is the time for our government to provide the same.”

This letter is only the lastest salvo in a war on ACTA that has accelerated across the globe. Also on Wednesday, Romanian Prime Minister Victor Ponta said that his government would not ratify ACTA—despite the fact that the European Union, of which Romania is a member, did sign it on his country’s behalf. Anti-ACTA protests have taken place in the Polish parliament and in cities throughout Europe.

EU ratification will come about if ACTA first passes the European Parliament, a body that asked for consultation by the European Court of Justice just last week. Meanwhile, Neelie Kroes, the EU commissioner for the digital agenda, expressed her skepticism that the 27-member bloc would ratify ACTA at all. Last week, Switzerland, which is not a member of the EU, said it too was backing away from the agreement.

Ars has reached out to the governments of New Zealand, Singapore, South Korea, and Morocco (other ACTA signatories) for their latest positions on ACTA, but as of press time had not received a reply. Six ACTA members need to sign before the agreement enters into force.

UPDATE: Matthew Hawkins, the first secretary to the Office of the Ambassador at the Embassy of New Zealand in Washington, D.C. wrote to Ars on Wednesday afternoon with this comment: "The New Zealand Government agreed to sign ACTA in June 2011, but to consider the issue of ratification separately at a later date. To date, the Government has not yet taken a decision on ratification because there are a number of parliamentary processes that still need to be worked through, including further public consultation."