Lib Dem leader in the Lords Dick Newby said: “Shirley Williams was a charismatic, committed and fearless politician who believed passionately in a fairer society and in Britain’s European destiny.

“She was an inspiration and mentor to many younger politicians and maintained her campaigning zeal to the end.

“She was central to the formation of the SDP and the Liberal Democrats, and will be greatly missed by many in her extended political family.”