Paetongtarn, the youngest daughter of former PM and Pheu Thai patriarch Thaksin Shinawatra, is set to be announced as one of the party’s three prime minister candidates on Wednesday.
Though not an MP candidate herself, she led Pheu Thai MP hopefuls to the registration centre at 6.35am, where they received a warm welcome from supporters.
Paetongtarn then urged Bangkokians to turn out in force for the May 14 election.
Opposition party Pheu Thai has targeted 310 of the 500 MP seats up for grabs nationwide, to form a single-party government and neutralise the power of the 250 junta-appointed senators.
"The people will decide how many seats Pheu Thai get," Paetongtarn said, adding that she was looking forward to seeing which registration numbers are handed to Pheu Thai MP candidates.
She confirmed the party would seek a landslide victory on May 14, while also thanking people for backing her to become Thailand’s 30th prime minister.
Paetongtarn has topped most opinion polls as people’s No 1 choice for PM, including a survey of Samut Prakan voters published on Sunday by Nida. Paetongtarn (35.82%) came top followed by Move Forward leader Pita Limjaroenrat (21.36%) and incumbent PM Prayut Chan-o-cha (13.91%).
"However, Pheu Thai will not be careless as anything could happen [in the election]," she said.
Paetongtarn added that Pheu Thai's victory in the Bangkok councillor election in May last year had created momentum for the party.
Pheu Thai won 20 Bangkok councillor seats, followed by Move Forward (12) and the Democrats (9).
She predicted Pheu Thai will also receive the majority of Bangkok votes in the upcoming election, even if she does not eventually become prime minister.
Real-state tycoon Srettha Thavasin has been tipped as Pheu Thai’s other likely candidate for PM.