Siobhan is the daughter of an Anglo-Indian mother and a Cornish father. She is a born-and-bred Londoner who was born in Merton and now lives in New Malden, Kingston with her husband and two daughters.
Siobhan joined the Civil Service in 1996, working at the heart of the government for many years. As a senior official at the Cabinet Office, she has worked with ministers and officials at the very highest levels and has devoted a lot of her time to improving gender equality in the workplace. She recently resigned from her senior Whitehall job to run in the mayoral election.
Siobhan prides herself on the fact that she is not a party politician. Unlike Boris Johnson or Ken Livingstone, she says that as Mayor of London she would not waste time fighting tired political battles. Instead, she wants to focus on the day-to-day concerns of Londoners, including prioritising education, improving transport, building safer neighbourhoods and increasing opportunities for businesses. Click here to read more about Siobhan's policies.
This web chat has now finished but you can read all the questions posed to Siobhan and her replies below