MANILA (REUTERS) - Philippine President Rodrigo Duterte might be barred from a second term in office, but don't be surprised if he's still running the country after a presidential election next year.

The popular Mr Duterte gave the strongest hint yet that he might seek the vice presidency, saying on Wednesday (July 7) that he was "sold to the idea" and thinking seriously about running for the largely ceremonial number two post.

For Mr Christian Monsod, a lawyer and one of the framers of the 1987 constitution, Mr Duterte's real intent is clear.

"There is a plan to use a backdoor approach to stay in power," he said.

Mr Duterte, 76, is trying to circumvent the single-six year term limit, set by the constitution to stop power from being abused, said Mr Monsod, a former election commission chief.

He suspects Mr Duterte was asked by allies to choose a running mate to campaign with to help the candidate win the presidency.

That president would then step down, allowing Mr Duterte to reassume the post.

Mr Duterte's spokesman and his legal counsel did not respond to requests for comment.

Mr Duterte, who has portrayed himself as a reluctant president with no desire for power, says he wants his media-shy longtime aide Mr Christopher "Bong" Go to be his successor.

His endorsement in 2019 helped Mr Go to become a senator, a job he combines with being Duterte's personal assistant. Mr Go says he is not interested.

Mr Duterte's daughter, Davao mayor Ms Sara Duterte-Carpio has outshone Mr Go in opinion polls as possible presidential contenders. But Sara and her father are against the idea of her running.

Mr Temario Rivera, head of the Centre for People Empowerment in Governance, said Mr Duterte's motivation to remain in power is obvious - to avoid jail and courtrooms.

Political vendettas are common in the Philippines and former leaders, minus their immunity of office, have been prosecuted and even jailed after changes in power.

"The question facing him is what is the best strategy to deal with that existential problem," Mr Rivera said.

Mr Duterte has repeatedly baited the International Criminal Court (ICC) and dared it to put him on trial for crimes against humanity. The ICC's prosecutor has since sought the go-ahead to launch a formal investigation into the drugs war killings.

"The strategy for Duterte is to make sure that the opposition does not win," Mr Rivera said.

"The ICC can now proceed with their investigation in a clearer manner if you have an opposition president in power."