Philippine President Rodrigo Duterte’s daughter has no intention of joining her father’s party or being its flag bearer, her spokesperson says, adding to the twists surrounding next year’s presidential election in the south-east Asian nation.

Mr Duterte said on Sunday he will not run for office and that he was leaving politics, adding that his daughter, Sara Duterte-Carpio, who is the mayor of Davao city, could run to replace him.

“Mayor Sara has no intention of becoming a member of PDP-Laban (Duterte’s party) or of being its standard bearer now or in the near future,” her spokesperson Christina Garcia Frasco said.

Ms Duterte-Carpio, 43, has said she will seek re-election as mayor of Davao, the Philippines’ third-largest city, but she is allowed under election rules to withdraw and register for a different position until November 15.

Two other presidential contenders , including newly retired boxing icon Manny Pacquiao, have so far filed their candidacies for president.

Mr Duterte’s long-time aide, Senator Christopher “Bong” Go, is a candidate for vice president, and the president referred to a “Sara-Go” ticket in a local media interview immediately after announcing his retirement plans.

Mr Duterte had planned to contest the vice president’s post, but his decision not to do so has been interpreted by political analysts as paving the road for his daughter’s presidential run.

He is not allowed to contest again for president.

Ms Duterte-Carpio, who has received offers from several politicians to run with her in next year’s polls, said last month she would not vie for a national post , having agreed with her father that only one Duterte would seek higher office.

The PDP-Laban party, which has yet to name its presidential bet, said its door was open for Ms Duterte-Carpio, who belongs to another party, to run for president under its banner.

“The decision is Sara’s to make,” party president Alfonso Cusi told Reuters.

Despite her repeated denials she was interested in becoming her father’s successor, Ms Duterte-Carpio remains by far the most popular presidential prospect, according to successive opinion polls this year.

“She is the only logical administration candidate … there must be some reason why she has been rating. Despite the many attacks against the administration, people know that she has her own independent politics from her father,” political analyst Edmund Tayao told Reuters.

Several analysts were not completely ruling out a last-minute presidential entry by Ms Duterte-Carpio that would mirror her father’s eleventh-hour bid in the 2016 campaign.

Mr Duterte, 76, is seen seeking to choose a successor he can fully trust to protect and insulate him from possible legal action, including from the International Criminal Court (ICC), once he is out of office.

Several Philippine presidents have been prosecuted and even jailed after leaving office.

The International Criminal Court has launched a formal investigation into the killings in Mr Duterte’s notorious drugs war.

The natural choice for Mr Duterte would be Ms Duterte-Carpio because she is “winnable”, but running with Mr Go, who has no support base and is trailing in opinion polls, would unlikely be the best move, said former political professor Temario Rivera.

But he said other alliances were also possible, including one between Ms Duterte-Carpio and the son and namesake of the late dictator Ferdinand Marcos, whose strong political base in the Philippines’ north could bring in more votes.

Former senator Ferdinand Marcos, who lost his vice presidential bid in 2016, ranked second and fourth in last month’s Pulse Asia survey of potential presidential and vice presidential contenders.

He has yet to make known his 2022 plans.