The Bush administration has announced its strong opposition to a bill backed by the recording industry that would let federal prosecutors file civil lawsuits against peer-to-peer pirates.

In a letter sent to the Senate Judiciary Committee on Tuesday that amounts to a veto threat, the administration said it was "deeply concerned" that the proposal would divert resources from criminal prosecution to civil enforcement, and create "unnecessary bureaucracy." Currently prosecutors have authority to file criminal charges.

The two-page letter said that copyright owners already have plenty of legal methods to target infringers, including seeking injunctions, impounding infringing materials, recovering actual damages plus statutory damages, and, in some cases, obtaining attorney's fees.

The letter was signed by Keith Nelson, a principal deputy assistant attorney general, and Lily Fu Claffee, the Commerce Department's general counsel.

The bill in question is called the Enforcement of Intellectual Property Rights Act, which the Senate Judiciary Committee approved in a 14-4 vote on September 11.

In addition, the administration said the bill was "objectionable on constitutional grounds" because it would create an "IP coordinator" inside the White House, the organization of which is traditionally a presidential prerogative.

It's relatively rare for a pair of federal agencies to oppose a bipartisan bill so strongly--Republican co-sponsors include Arlen Specter and Orrin Hatch--and the implied threat of a veto is likely to doom the proposal in its current form.