A couple of weeks ago, the New York State Bar Association issued an ethics opinion with an answer to this interesting question: can the same law firm file amicus briefs on both sides of a Supreme Court case?
And the answer is, as it so often is,... "it depends."
The question originated when a law firm asked its lawyers if any of them would be interested in preparing an amicus brief for filing with the Court. The problem was that some lawyers wanted to argue one side of the issue, while others wanted to argue the opposite side.
Given the division of opinions, the firm management decided to create two separate teams to work on their respective positions and then to ask the NY State Bar Association Ethics Committee if they could file both briefs.
In it opinion (Opinion 1174), the Committee concludes that the firm can't file either brief if two clients ask the firm to submit amicus briefs on opposing sides of an issue because New York’s Rule 1.7 bars a lawyer from representing clients on both sides of the same litigation.
However, in this case the interest in filing the briefs did not come from a client request. Here, the lawyers were to appear pro se. Thus, as long as the attorneys appeared in their own name, rather than in the firm's name, the Committee found no ethical reason why attorneys may not file amici briefs on opposing sides of a question before the Court.
You can read the opinion here. The Law For Lawyers Today has a post on the opinion here.
Meanwhile, over at Faughnan on Ethics, Brian Faughnan argues that it is not clear what the answer would be if one lawyer from the firm was filing on behalf of a client and then another lawyer in the same law firm wanted to file an opposing brief pro se. If it is true that lawyers are "as free as anyone" to file pro se briefs in any cases, it would seem that the answer is that the pro se lawyer would be allowed to file the amicus brief. Yet, this situation would look too similar to having an attorney from a firm arguing on both sides of the "v." in a litigation matter.