For Helmut Kohl, she was always das Madchen, the girl, an unassuming pastor's daughter who became one of a handful of easterners to join the former chancellor's cabinet. But as she prepares to be anointed chairman of Germany's opposition Christian Democrats (CDU) later this month, Angela Merkel is emerging as a formidable politician who could rob the Chancellor, Mr Gerhard Schroder, of a second term in office.

An opinion poll this week put Dr Merkel at level pegging with the Chancellor, a remarkable finding in view of the scandal over the CDU's illegal funding of election campaigns. But her appeal is such that, according to Klaus-Peter Schoppner, head of the Emnid polling institute, it defies the laws of political allegiance.

"Germany is ready for a new political style whereby democracy finally becomes politics for people by people rather than self-interest and technocracy. Nobody embodies this new politics better than Angela Merkel. If virtue is accompanied by the right issues, she could even put an end to the German sickness of political apathy," he said.

Dr Merkel owes her leadership position to the courageous stand she took last December when she became the first prominent Christian Democrat to call for a clean break with the legacy of her political godfather, Dr Kohl.

She was roundly abused by the former chancellor's allies at the time, but as details of Dr Kohl's financial irregularities piled up, forcing Dr Wolfgang Schauble to resign as CDU chairman, Dr Merkel emerged as the party's favourite to lead it into a new, sleaze-free era.

Dr Kohl's fall from grace has been so dramatic that he has cancelled all celebrations planned for his 70th birthday and will not even be receiving well-wishers at home. And the funding scandal has tainted so many of the former chancellor's erstwhile friends that the CDU has been forced to turn for salvation to the unlikely figure of a Protestant woman from the formerly communist east of the country.

Born in the beautiful but impoverished state of Mecklenburg in 1954, Dr Merkel grew up within East Germany's beleaguered Christian minority. As a pastor's daughter, she was not expected to join the ruling Socialist Unity Party and she showed little interest in politics until the final months of the communist state.

When she finished her physics studies at Leipzig University, Dr Merkel moved to Berlin to work at the Academy of Sciences until she left academic life in 1990. As popular resistance against the East German regime grew in 1989, she joined a dissident group called Democratic Breakthrough before joining the CDU in 1990.

She was deputy spokesman for Lothar de Maiziere's short-lived, democratically elected, East German government in 1990 and was elected to the Bundestag in the first all-German election later that year.

Dr Kohl appointed her Minister for Women's Affairs in 1991 and promoted her to Environment Minister in 1994, but she made few interventions at cabinet and was often dismissed by male colleagues as "a little Ossi mouse". But Dr Merkel soon won a reputation in Bonn for her hard work, straight dealing and sharp intellect.

"I learned better in the German Democratic Republic to read between the lines than to make headlines myself," she said. Colleagues say that she is entirely lacking in guile and that her face reflects her every emotion, so that she cannot conceal impatience or irritation during leadership meetings.

Dr Merkel can look forward to an enthusiastic coronation at the CDU party conference in Essen later this month, but her honeymoon is unlikely to last long. Dr Kohl's legacy of scandal has done severe damage to the CDU's reputation among voters, and the party faces likely defeat next month at an election in Germany's most populous state, North Rhine-Westphalia.

Although her former rivals for the leadership have been loud in their praise for Dr Merkel in recent weeks, she can count on little loyalty from most of the party's political heavyweights. Mr Schroder's friends whisper that Dr Merkel is little more than a Trummerfrau, one of the women who rebuilt Germany from rubble after the end of the second World War. Once she has restored the damaged house of Christian Democracy, the old, western, male establishment will reclaim it for themselves.

The Bavarian Prime Minister, Edmund Stoiber, has been among the loudest in protesting his support for the new CDU leader, but few observers doubt that he harbours ambitions to stand as the conservative candidate for chancellor in 2002. Many of Mr Stoiber's friends are suspicious of Dr Merkel, whom they regard as too liberal on such issues as women's rights, abortion and the legal status of gay partnerships.

Dr Merkel has benefited throughout her career from being underestimated by her rivals and dismissed as an amateur who lacks the essential skills of the modern politician. As he watches his opinion poll lead disappearing week by week, Mr Schroder is unlikely to be so dismissive of his new adversary.