Moon Seung-keun, acting chair of the main opposition Democratic United Party, on Tuesday offered Ahn Cheol-soo admittance into the liberal bloc’s presidential nomination process, calling the IT guru a comrade.

Speaking on a radio program, he said there were ways for him to win the party’s backing in the December presidential election without actually joining the party.

“In a broad sense, we are comrades and we should join hands (for the presidential race),” the politician said, citing Ahn’s past criticism of the incumbent administration of President Lee Myung-bak and his ruling Saenuri Party.

To oust the Saenuri from power, all liberal forces must unite behind a single candidate and Ahn should join this process, Moon said.

“One way of doing so is to set up a paper party which encompasses all liberal presidential contenders and hold an open primary,” the politician explained.

A former actor and staunch supporter of late liberal President Roh Moo-hyun, Moon stepped in as acting chair of the opposition group after its leader Han Myeong-sook resigned Sunday over the party’s disappointing performance in the April 11 general election.

His offer came a day after a local media report that Ahn, dean of Seoul National University’s graduate school of Convergence Science and Technology, had made up his mind for a presidential bid and started recruiting allies for his camp.

Ahn remained silent Tuesday, neither confirming nor denying the report.

A person close to him, however, expressed worries over “speculative” media reports.

“It is natural for him to seek advice on political and social issues of our society as part of his efforts to find a way to contribute to society,” Yonhap News reported, quoting an unnamed source.

“I understand there was no change in his stance since he spoke the last time.”

In March, Ahn said during a lecture that he could endure politics, if that is a way for him to contribute to bettering society.

The remark was the biggest hint yet from the 50-year-old businessman-turned-scholar, who has been ambiguous about his political ambitions, although he enjoys more popularity than any opposition politician considered a potential presidential candidate.

Talk of Ahn’s presidential bid jolted the DUP, as many of its members regard only Ahn as a match for Park Geun-hye, Saenuri’s chief and the clear favorite for the presidential ticket.

For nine months, most opinion polls had placed him above Park in a hypothetical matchup for the Blue House, but the latest polls have shown Ahn trailing Park.

Politicians across the aisle urged him to make clear his intentions and end unconstructive speculation surrounding him.

One of them was Kim Jong-in, a member of the ruling Saenuri Party’s chief decision-making Supreme Council who was once known as one of Ahn’s mentors.

“It is not a good attitude for an aspiring politician to drag on like this, causing confusion among people with ambiguous words,” he said.

He went on to play down Ahn’s popularity, saying even if a two-way contest is realized between Ahn and Park, he would not be a big threat to her.

“Ahn is generally popular among people, but as a presidential candidate, he will be checked on his presidential credentials, past conduct and so on. Who knows what comes up,” he said.

Sim Sang-jeong, one of the co-chairs of the minority Unified Progressive Party, also said it was time for him to decide.

“If he is ever going to run, he should make it clear as soon as possible,” she said.

By Lee Sun-young (milaya@heraldcorp.com)