South Korean prosecutors have sought a formal arrest warrant for a man suspected of slashing the face of South Korea's main opposition leader.
The attack provoked a public outpouring of anger
One official was quoted as saying they were pursuing the warrant against Ji Choong-hu on attempted murder charges.
Park Geun-hye, of the Grand National Party (GNP), was assaulted with a box cutter at a campaign rally on Saturday.
She is recovering in hospital after receiving an 11cm (four-inch) gash to her cheek.
Chief suspect Ji Choong-hu was detained at the scene and has been questioned over the attack.
Prosecution official Nam Ho-hyun said the authorities were seeking an arrest warrant on charges of attempted murder, which could mean a sentence of more than five years for Mr Ji if convicted.
Senior prosecutor Lee Seung-ku said earlier he would also be seeking a formal arrest warrant for another man arrested at the scene, Park Jong-yeol, a card-carrying member of the Uri party.
Mr Lee said both men denied knowing each other.
Park Geun-hye was climbing the steps to a podium at a campaign rally ahead of 31 May local elections, when the attack happened.
A hand shot up from her right and swung across her cheek, Reuters news agency reports.
She reportedly needed 60 stitches for the gash and doctors say she will be unable to speak normally or chew for several weeks.
Hospital official Park Chang-il said on Monday she was "recovering fast".
"She still complains of frequent pain, but she seems to have quite stabilised," the official said.
The attack has provoked an outpouring of public outrage and sympathy for Ms Park, who is seen as a likely candidate for the 2007 presidential election.
The 54-year-old is the daughter of former President Park Chung-hee, who was assassinated in 1979. Her mother was fatally shot five years earlier.
Ms Park said there should be no assumption that the assault was politically motivated, the GNP said in a statement, but the party leadership called it a "premeditated attempt" on her life.
The ruling Uri Party, which has terminated Park Jong-yeol's membership, expressed regret for the attack but warned the GNP against using the assault for "political purposes".