Thirty-four-year-old Stanislav Gross looks poised to become the next Czech prime minister, and with it one of the youngest leaders in Europe.
Stanislav Gross has risen through the party ranks
The former train technician, once described as the "crown prince" of the Social Democrats, is one of the country's most popular politicians who has risen quickly through the party ranks.
The resignation of Vladimir Spidla as prime minister and party leader has opened the door to a post for which Mr Gross has been reluctant to make an overt bid - despite being openly criticial of Mr Spidla's leadership style in the past.
Last year, he admitted he was not sure he was capable of running his party and the country at the same time.
Already installed as party leader, he now appears to be making a concerted effort to become the next prime minister too.
Mr Gross, who has a reputation as a skillful negotiator, says he wants to keep the same two centre-right partners which backed the outgoing cabinet.
He has also said he wants to build a government that would not rely on Communist support, already falling into line with one of President Vaclav Klaus' key requisites for the post.
There seems to be little love lost between the outgoing Mr Spidla and Mr Gross, with the now former prime minister saying he would be "hardly" likely to accept a post in a cabinet led by the young contender.
But he declined to comment when asked on Czech Radio whether he felt betrayed by Mr Gross.
Mr Gross was born in Prague, where he worked briefly as a trainee railway technician after finishing school.
After national service he went into politics, joining the re-established Social Democratic Party where was elected chairman of the Young Social Democrats in 1990.
He rose through the ranks of the senior party in the late 1990s, with posts including chairman of the group of deputies (Party Whip) and vice-speaker.
He has also been party spokesman for the department of security.
From April, 2000 he spent two years as interior minister. At the party congress in 2001, he was elected statutory vice-chairman.
He is married with two daughters.