It is rare for the Office of the Solicitor General to change its position in a case before the Supreme Court after a change in administrations, even when the party in control of the White House changes. But that is exactly what happened last week, when the Trump administration weighed in on an important arbitration case: The office urged the justices to affirm the same decision that, on behalf of the National Labor Relations Board, it had previously asked them to review and overturn.

The about-face came in National Labor Relations Board v. Murphy Oil USA, in which the justices have agreed to decide whether agreements to forgo class actions or collective proceedings and instead resolve employer-employee disputes through individual arbitration are enforceable under the Federal Arbitration Act. In its petition for review on behalf of the NLRB, filed in September 2016, the Solicitor General’s office had argued that such agreements are not, because the National Labor Relations Act protects employees’ ability to engage in joint actions regarding the terms or conditions of their employment. On January 13, 2017, just seven days before the inauguration of President Donald Trump, the Supreme Court granted the NLRB’s petition, along with two others filed by employers (Ernst & Young LLP v. Morris and Epic Systems v. Lewis), and consolidated the three cases for one hour of oral argument.

Under the briefing schedule ordered in the case, the employers in all three cases filed their briefs on June 9, with briefs from the employees and the NLRB to follow on August 9. But on Friday (the deadline under the court’s rules to do so), the United States filed a “friend of the court” brief supporting the employers. The petition for review had been signed by seven lawyers from the NLRB, including its general counsel. Those NLRB lawyers were conspicuously absent from Friday’s brief, which was signed only by lawyers from the Solicitor General’s office. Acting Solicitor General Jeffrey Wall acknowledged that his office had previously filed a petition on behalf of the NLRB, “defending the Board’s view that agreements of the sort at issue here are unenforceable.” But, Wall continued, “since the change in administration, the Office reconsidered the issue and has reached the opposite conclusion.” In particular, Wall explained, the NLRB had not given “adequate weight to the congressional policy favoring enforcement of arbitration agreements that is reflected in the” Federal Arbitration Act.

In a press release published on the NLRB’s website, the NLRB indicated that Wall had authorized it to represent itself in the Supreme Court proceedings in this case, and nothing in the brief of the United States suggests that the NLRB has changed its position. This means that the NLRB is likely to file its own brief, reiterating its original position in the case, in early August. And if the United States seeks and receives permission to argue in the case, as it virtually always does in cases in which it files “friend of the court” briefs, a lawyer for the United States would argue against a lawyer for a U.S. agency – a phenomenon perhaps even more uncommon than a change in position following a change in administration.