Susan Kramer brings her business experience to her job as MP
Susan Kramer has the distinction of being the only woman, so far, spoken about as a serious candidate for the Liberal Democrat leadership.
The 57-year-old former banker has ruled herself out of the race but has a reputation as a moderniser who is used to tough fights.
As the Lib Dems' candidate for London mayor in 2000, she spent many hours tramping the streets in orange Dr Martens in an, ultimately unsuccessful, effort to energise her party's vote.
She admitted at the time to having a "peculiar genetic defect" that made campaigning a real pleasure for her.
She championed US-style community banks to help poor families get credit and claims that the other mayoral candidates learned from her idea to raise Tube finance by issuing bonds.
"I got up at six in the morning and went through to midnight for nine months. I got a tremendous kick out of it," she said.
In 2005, her political ambitions took another direction and she secured the parliamentary seat of Richmond Park in south west London for the Lib Dems after its previous incumbent Jenny Tonge stood down.
She has built a good reputation as an MP, contributing to an above-average number of debates and asking many questions of government ministers.
Earlier this year Ms Kramer, a party spokeswoman on transport issues, was also one of the few MPs not to claim any travel expenses after figures revealed that some members were claiming more than £40,000 a year.
Along with fellow Lib Dems Nick Clegg and Chris Huhne, she is one of the authors of the famous "Orange Book", which sets out a more free market policy agenda for the party.
Using her banking experience, she contributed a chapter on harnessing markets to achieve environmental goals.
Privately educated at St Paul's School and with an Oxford degree under her belt, she took an MBA at the University of Illinois and went on to become a vice-president of Citibank Chicago.
A widow since last year, Ms Kramer has two grown-up children. Her son, who lives near her in Barnes, has previously helped to organise her campaigns.