Harvard Law School professor Vicki C. Jackson filed an amicus brief Thursday arguing that the U.S. Supreme Court does not have the constitutional power to rule on United States v. Windsor, the landmark case challenging the way marriage is defined in the Defense of Marriage Act.

In the 40-page filing, Jackson argued that the justices do not have the jurisdiction to hear the case because President Barack Obama’s administration, which has stopped defending the controversial law, agrees with a lower court ruling deeming DOMA unconstitutional.

Jackson’s brief also contends that the Bipartisan Legal Advisory Group, a Republican majority body in the House of Representatives, does not have legal standing to defend DOMA under Article III of the Constitution because Congress does not have the right to defend laws which do not specifically relate to its duties.

According to the brief, “the interest here in assuring that [DOMA] is enforced is a generalized one” which falls under the domain of the executive branch, not that of Congress.

At press time, Jackson could not be reached for comment on the brief.

The United States v. Windsor case addresses the constitutionality of section three of DOMA, which states that “the word ‘marriage’ means only a legal union between one man and one woman as husband and wife, and the word ‘spouse’ refers only to a person of the opposite sex who is a husband or a wife.’”

In particular, the justices are slated to rule on whether DOMA violates the Fifth Amendment’s equal protection component of the due process clause by excluding same-sex couples legally married in their own state.

The Court asked Jackson to write the brief shortly after it agreed to hear two cases addressing gay marriage, United States v. Windsor and Hollingsworth v. Perry, a case challenging California’s Proposition 8.

The Court will hear the oral arguments for Hollingsworth v. Perry on March 26 and United States v. Windsor on March 27. It is expected to issue decisions on both cases in June. If the justices take Jackson’s advice, however, they will likely not have time to rule on another DOMA case this year.

Jackson, who has published extensively on constitutional law and the Supreme Court, joined the Law School faculty as a professor in 2011 after working at the Georgetown University Law Center. This semester, she is scheduled to teach “Comparative Constitutional Law” and a seminar called “Proportionality as a Transnational Principle,” according to the Law School course catalog.

—Staff writer Dev A. Patel can be reached at devpatel@college.harvard.edu.