In a unanimous 15–0 ruling delivered on Friday, the court found that the impeachment complaint endorsed by the House earlier this year violated the “one-year rule” under the 1987 constitution, which prohibits multiple impeachment proceedings against the same official within a 12-month period.
While both chambers of Congress said they would not appeal against the decision, the House of Representatives immediately vowed to refile the impeachment complaint early next year.
The full ruling has yet to be released, but court spokeswoman Camille Ting said the justices concluded that due process “applies during all stages of the impeachment process” and reminded the House that “there is a right way to do the right things at the right time”.
“Our fundamental law is clear. The end of it does not justify the means,” Ting quoted the court as saying.
She did not elaborate on how the House had run afoul of the one-year rule, but said the violation meant the Senate “could not acquire jurisdiction over the impeachment proceedings”.