Shirley Williams, leader of the Liberal Democrats in the House of Lords

Baroness Williams was elected leader of the Liberal Democrats in the House of Lords last November. She was previously deputy leader.

Baroness Williams' victory in the two-horse race makes her the third successive member of the SDP 'gang of four' to take the post. Her predecessors Bill Rodgers and Roy Jenkins were fellow members of the quartet that broke away from Labour in 1981 to found a new party aimed at displacing it.

As a senior member of the Liberal Democrats Baroness Williams' support for Charles Kennedy's candidacy as leader was invaluable.

Once tipped to be Britain's first female prime minister, she speaks strongly on social injustice, poverty and women's rights.

Indeed, she has first hand experience of being a single mother while a minister in Jim Callaghan's Labour government.

Since 1992 she has sat in the House of Lords as a Liberal Democrat life peer with the title Baroness Williams of Crosby.

She is married to the American academic, Richard Neustadt, and they divide their time between the US and Britain.

As well as foreign affairs spokeswoman she is a board member of the International Crisis Group.

She is an active campaigner for Britain to join the single currency, and is a member of the Britain in Europe campaign.