well-founded claim . . . .” Pryor v. Brignole, 346 Conn.
534, 545, 292 A.3d 701 (2023).
The Judicial Branch’s interlocutory appeal from the
ruling of the commission’s referee to the trial court
regarding its claim of immunity from suit satisfies the
second prong of § 4-183 (b). A colorable claim of a sepa-
ration of powers violation resulting from a coordinate
branch’s exercise of jurisdiction raises not only a consti-
tutional defense, but also an immunity from suit in the
forum of the coordinate branch. “[T]he essence of the
protection of immunity from suit is an entitlement not
to stand trial or [to] face the other burdens of litigation
. . . .” (Citation omitted; internal quotation marks omit-
ted.) Trinity Christian School v. Commission on Human
Rights & Opportunities, supra, 329 Conn. 693–94. To
challenge an administrative agency’s exercise of juris-
diction on separation of powers grounds is to claim an
entitlement to be free of the agency’s authority alto-
gether. But cf. Office of the Governor v. Select Committee
of Inquiry, 271 Conn. 540, 578, 585–86, 858 A.2d 709
(2004) (holding that governor did not have “categorical
immunity” from legislative subpoena under separation of
powers doctrine because legislature was “exercis[ing] the
impeachment power with which it has been entrusted”).
In this case, if the commission’s exercise of jurisdiction
is itself a separation of powers violation, the interference
in the essential functions of the Judicial Branch caused
by the commission proceedings could not be meaningfully
remedied by later judicial review. Because parties must
have structural recourse to vindicate their right to be
entirely free of a forum when its exercise of jurisdiction
violates the separation of powers doctrine, the appropri-
ate remedy is absolute immunity from suit in that forum,
a claim that is immediately enforceable in the courts of
this state. See, e.g., Stamford v. Commission on Human
Rights & Opportunities, Office of Public Hearings, supra,
351 Conn. 314 n.12; Trinity Christian School v. Com-
mission on Human Rights & Opportunities, supra, 329
Conn. 693. Although functionally similar to other types
State of Connecticut, Judicial Branch v. Commission on Human Rights &
Opportunities, Office of Public Hearings