Baleka Mbete probably thought celebrations for this week would be confined to her 59th birthday. Instead she could find herself the new President of South Africa and the nation's first female leader.

Mrs Mbete, the parliamentary speaker and ANC chairman, is hot favourite for the presidency following the forced resignation of Thabo Mbeki.

A decade ago, it all looked so different for the politician from Durban. Revelations that she had acquired her driver's licence fraudulently threatened to scupper Mrs Mbete's political career. Reportedly "too busy" to stand in queues, the ANC stalwart was accused in 1997 of paying a corruption-riddled testing centre to obtain her permit. Although a subsequent investigation found that her driver's licence had been issued improperly, Mrs Mbete was not charged with any wrongdoing, and faced down opposition calls for her to resign.

Mrs Mbete, who has five children, began her career as a teacher, working in the classrooms of her home town, but it was in the ANC that she found her calling. Like many prominent ANC party activists, she went into exile during the dark days of apartheid, leaving South Africa in 1976 and moving between Swaziland, Tanzania, Kenya and Botswana.

But when the ban on the ANC was lifted in 1991, she returned home, helping to re-establish the Women's League. As one of the leading female figures in the ANC, she took part in the long negotiations that brought democracy to South Africa and was elected to parliament in the first post-apartheid elections in 1994.

She played a key role in drafting South Africa's new constitution and in 1996 became deputy speaker of the parliament before being promoted to speaker in 2004.

Mrs Mbete would be South Africa's first female leader, and the second female president on the continent after Liberia's Ellen Johnson-Sirleaf. The South African politician flew across the continent to witness Mrs Johnson-Sirleaf's inauguration in 2006, and provoked another storm of controversy in the process. She chartered a private jet, at a cost of 471,000 rand (£32,600) to take her and a member of her staff to Monrovia for the ceremony, prompting an outcry in the press about her jetset tastes and her refusal to suffer the inconveniences of scheduled air travel.

Mrs Johnson-Sirleaf has earned many plaudits for her stewardship of Liberia, which is struggling to recover from years of bloody civil war. Mrs Mbete's stint in office will be much shorter, in terms of both time and accomplishments. She is there purely to preside over the transition between Mr Mbeki and Jacob Zuma, who although leader of the ANC, cannot yet take over the running of the country because he is not a member of parliament. An ardent Zuma loyalist, Mrs Mbete was at the High Court in Pietermaritzburg on 12 September to witness the judgment that sounded the death knell for Mr Mbeki's presidency. Now she will keep the presidential seat warm for his arch-rival.

By Claire Soares