By Ed Cropley
JOHANNESBURG (Reuters) - If it was a declaration of a bid to become president of South Africa, it was a very strange one.
After weeks of speculation that he is lining up a challenge to President Jacob Zuma in an African National Congress (ANC) leadership election in December, Deputy President Kgalema Motlanthe attracted a packed house at the launch of an official biography on Thursday night.
To the hundreds of supporters jammed into the auditorium at Johannesburg's Wits University, his remarks were affirmation that Motlanthe is taking up the mantle of an "Anyone But Zuma" campaign dividing the ruling party in Africa's biggest economy.
To the less partisan observer, his comments were more notable for their obscurity and ambiguity, even by the standards of a 100-year-old liberation movement with a habit of talking in code forged in the long underground struggle against apartheid.
Foregoing the chance to comment on the labor unrest sweeping through the mining sector, Motlanthe - once head of the biggest mining union - instead embarked on a rambling anecdote about alternative learning techniques that he had seen this week on an official visit to a school in Italy.
"From a very early age, these children will learn that things are always changing," he said, to cheers from supporters for whom "change" means "challenge to Zuma" at the ANC conference in Mangaung, near Bloemfontein.
With a wry smile, Motlanthe then professed his ignorance of the double entendre. "The irony is really lost on me," he said, to laughter from the hall.
Motlanthe, a bearded and bespectacled 63-year-old, exudes a solidity that reassures the business community.
He has already had one brief stint as president following the ANC's unceremonious ejection of Thabo Mbeki, mid-term, in 2008, although he did little more than serve as a place-holder for Zuma.
He also has impeccable "struggle credentials", having spent 10 years imprisoned on Robben Island with Nelson Mandela for being a member of the ANC's armed wing, Umkhonto we Sizwe.
However, he remains an inscrutably private figure and has seldom revealed his views on economic policy beyond the left-leaning intellectualism that prevails among most ANC leaders.
At the book launch, he drew more cheers when he said he had recently read "The Life of a Useless Man" - either a reference to a 20th-century Russian novel by Maxim Gorky, or a swipe at Zuma, widely criticized for his handling of the worst mining unrest since the end of white-minority rule in 1994.
ANC branches in two of South Africa's nine provinces have already come out to propose Motlanthe as the next leader of the party, a position that would tee him up to become head of state in the 2014 election.
However, the big regions, including Zuma's home province of KwaZulu Natal, have yet to express a preference, leading most analysts to presume that Motlanthe is doing some careful electoral sums before throwing his hat in against the favorite.
With as much as six weeks to run before the party compiles its final list of leadership candidates, the ambiguity - and the government paralysis that it entails - looks set to run and run.
The book launch triggered another round of "Motlanthe hints" headlines in papers that have become highly critical of Zuma, with editorials calling almost daily for decisive leadership to tackle South Africa's huge social and economic problems.
Whether Motlanthe is the man to provide that remains to be seen.
"And that's that," radio anchor Stephen Grootes concluded on Twitter after the book event. "Typically cryptic Motlanthe."
(Reporting by Ed Cropley; Editing by Kevin Liffey)