Manila, June 12 -- The Philippine Constitution Association (Philconsa) on Thursday said the Senate, sitting as an impeachment court, raised constitutional concerns when it returned the impeachment complaint against Vice President Sara Duterte to the House of Representatives.

In a statement, Philconsa, through its chairperson former chief justice Reynato Puno, said the Senate's action "raises grave constitutional questions and challenges the integrity of the impeachment process."

"Philconsa warns that it may constitute grave abuse of discretion and risks undermining the most fundamental principle of our constitutional democracy: that Public Office is a Public Trust," Puno said.

"The Accountability of Public Officials cannot be overstres...