An MP since 2005, Susan Kramer has been a high-profile Liberal Democrat for far longer.
She stood unsuccessfully for London mayor in 2000 and was a board member of Transport for London.
Now MP for Richmond Park, Oxford-educated Ms Kramer was a vice-president of Citibank.
She has been involved in setting up an environmentally sensitive waste recycling waste water-recycling project in Hungary.
She was previously the Lib Dem spokeswoman on international development.