The right of companies to use key elements of computer code, known as application programming interfaces (APIs), was cast deeper into doubt on Tuesday after the Justice Department urged the Supreme Court not to hear a controversial case that pits Google GOOG and a long list of supporters against Oracle ORCL .

The news came after the Supreme Court asked the Obama Administration in January to weigh in on a lower court ruling last year that favored Oracle, and shocked many in the tech industry.

The issue before the court is when, if at all, APIs can be protected by copyright. The outcome has serious repercussions not just for Google, but the entire software industry, since APIs act as a sort of lingua franca that allow different computer programs to deliver instructions to each other.

In the case of Oracle and Google, the dispute turns on the search giant’s use of certain Java APIs for its Android software. Java is a programming language that was developed by Oracle’s predecessor, Sun Microsystems, and is widely used by software developers.

Google, backed by tech trade groups and law professors, does not dispute that computer code can be copyrighted. The parties argue instead that Google only used a small portion of Oracle’s Java Standard Library, and did so only in order to use common signposts or headers, rather than reinventing the instructions from scratch. The argument, in effect, is that developers should be able to use these small chunks of code, which serve as industry standards, free of copyright restrictions.

U.S. District Judge William Alsup, a respected Silicon Valley judge, initially sided with Google in 2012 after teaching himself Java for the trial. He found that the APIs were functional, and fell on the wrong side of copyright law’s “idea/expression dichotomy” and merger doctrine – these are rules that prevents copyright law from becoming too broad, and covering everyday things like menus and simple instructions.

Last year, however, the U.S. Federal Circuit appeals court overturned that finding, and likened the Java APIs to Charles Dickens and other literary works. The ruling drew widespread scorn at the time:

In its filing on Tuesday, the Obama Administration’s top lawyer sided with the Federal Circuit. It also repeated that court’s argument that the case should be decided by determining if Google had a “fair use” right to use the APIs.

This fair use approach is unacceptable to many in the tech community since it would fail to draw a bright-line rule for APIs, and would force developers to take frequent risks in using common pieces of code.

The Solicitor General’s recommendation, which reportedly came after ideological fights within the White House, does not necessarily mean the Supreme Court will refuse the case. But, since the Court typically looks to the Solicitor General for guidance, Tuesday’s filing diminishes the chance that Google’s appeal will be heard.

A Google spokesperson issued the following statement: “We appreciate the Solicitor General’s careful review of this issue, however we’re disappointed with these conclusions. We still look forward to defending the concepts of interoperability that have traditionally contributed to innovation in the software industry.”

In its own statement, Oracle said in part, “The Solicitor General’s brief agrees with the Federal Circuit’s decision and affirms the importance of copyright protection as an incentive for software innovation.”

The Court will likely say whether it will hear the case in the coming months.

Here’s a copy of the filing:

Goog v Oracle, Solicitor General Brief Copy