People demonstrate in demand of the resignation of Guatemalan President Otto Perez as a corruption scandal rocks the government, at Constitution Square in Guatemala City on May 16, 2015. (AFP)
Guatemalan President Otto Perez said on Monday he is calm and confident he has done nothing wrong, as lawmakers debated stripping his immunity and forcing him to face prosecution on corruption charges.
"I reiterate yet again my position on the allegations made by the prosecution, and it is that I am completely calm," he told a press conference.
The conservative president has faced mounting calls for his resignation since UN investigators accused him of running a massive fraud scheme at the national customs service, a scandal that has already felled his former vice president and caused nearly half his cabinet to resign.
His latest denial came after a congressional investigative committee recommended Saturday that he be stripped of his presidential immunity and prosecuted.
The decision now moves to the full legislature, where 105 lawmakers out of 158 would have to vote in favor of such a resolution.
Just before Perez's press conference, his lawyer filed a motion with the Constitutional Court to block the vote, which is expected in the coming days.
Investigators say Perez, arrested ex-vice president Roxana Baldetti and a raft of other top officials operated a scheme in which businesses paid bribes to clear their imports through customs at a fraction of the actual tax rate.
Perez, a 64-year-old retired general and the founder of the Patriotic Party, has apologized for the fact the graft happened on his watch, but denies involvement.
He has repeatedly rejected calls to resign before his term ends in January -- a stance he reiterated on Monday.
"I have not received a cent from this fraudulent system, which was practically robbing the people," Perez said.
"There's something important here, and that is the presumption of innocence until proven guilty."
The turmoil comes as Guatemala prepares for elections on Sunday that will decide Perez's successor.
The president, who has been in office since 2012, is constitutionally barred from running for reelection.
The scandal has triggered weeks of mass protests.
Perez said he understands the protesters' outrage, but urged "each individual to reflect... on whether (the accusations) are true or not."