A team from Jenner & Block has formally joined the U.S. House’s lawsuit seeking to compel testimony from former White House counsel Don McGahn, as the case heads to en banc arguments before the U.S. Court of Appeals for the D.C. Circuit later this month.

Matthew Hellman, co-chair of the firm’s appellate and Supreme Court practice, and Elizabeth Deutsch, formerly a fellow with the ACLU, filed a notice of appearance in the case Thursday. Their names were also both included on a brief filed by House lawyers later that afternoon.