Paetongtarn’s office asked the constitutional court for a deadline extension, secretary-general Prommin Lertsuridej told reporters today.
The court has not yet responded to the request or specified how much more time it will give, he said.
“We’ve requested an extension today, but by how long is up to the court,” Prommin said.
“It’s within our rights to do so, as we couldn’t prepare the statement in time.”
The court suspended Paetongtarn from prime ministerial duties on July 1 and gave her 15 days to submit a written response.
It acted after a group of senators submitted a petition accusing Paetongtarn of violating ethical standards over her remarks in a leaked phone call with former Cambodian leader Hun Sen.
The youngest daughter of billionaire and former premier Thaksin Shinawatra, Paetongtarn faces disqualification and removal from office if the court finds her guilty.
The court case is the biggest threat yet to Paetongtarn’s nascent political career and less than year-old government.
She came to power in August last year after her predecessor, Srettha Thavisin, was ousted in a similar ethics-related case over an appointment of a cabinet minister.
Paetongtarn’s coalition government was plunged into a crisis when Hun Sen leaked the phone recording of his conversation with the Thai leader.
Critics say she appeared to be siding with Hun Sen and criticising the Thai army while discussing solutions to a simmering border dispute with Cambodia.
That angered conservative-leaning activists and opponents, who organised the biggest public protest in years to demand her ouster.
The suspended premier also reportedly faces a separate probe by the national anti-corruption commission over the same allegations of ethical violations.
If the panel determines that there is sufficient evidence, it may formally charge Paetongtarn and refer the case to a division of the Supreme Court for adjudication.
Past rulings by the court in similar cases have led to lifelong bans on Thai politicians from holding or running for public office.