Ban Ki-moon only just arrived in South Korea on 12 January after stepping down from his position as UN secretary-general but already there is a loud call for him to join the presidential race. A Gallup Korea poll released on 13 January placed him second in a survey of South Korean presidential favourites. He ranks 11 percentage points behind former opposition leader Moon Jae-in, who is currently leading the survey at 31%.

Ban has still to reveal plans for his political future and has made no mention of running in the election nor has he affiliated himself with any political party.

Ban Ki-moon
Former UN chief Ban Ki-moon waves to his supporters as he leaves after a news conference at the Incheon International Airport in Incheon, South Korea REUTERS/Kim Hong-Ji

"I've been saying I will listen to our people's thoughts after returning home. I will have that opportunity from tomorrow. I will make a selfless decision with a humble heart," Ban said on his arrival in Seoul."That decision-making won't take long."

On Friday, the 72-year-old visited the Seoul National Cemetery and the community centre. After spending a decade living in New York, he is now required to register his residence in Seoul.

South Korea has been in the midst of political turmoil following the impeachment of President Park Geun-hye on corruption charges. If upheld by the Constitutional Court, the motion could trigger an early presidential election.

Even before having the opportunity to throw his hat into the presidential ring, Ban has already had to face scandal in the form of allegations that his younger brother, Ban Ki-sang, and nephew, Joo Hyun Bahn, were involved in a scheme to bribe a Middle Eastern official in connection with the attempted $800m (£658m) sale of a building complex in Vietnam. Ban on his part has denied any knowledge of his realtives' affairs and said he was "perplexed and embarrassed" by their involvement.

The Friday poll which was conducted from January 10 to 12, has taken into account these accusations of bribery against his relatives.