Allegations of sexual abuse have been made against Sir Cyril Smith in a new book by the Labour MP for Rochdale, Simon Danczuk.
Sir Cyril was previously a Liberal Democrat MP for the same constituency, and allegedly raped boys at Knowl View residential school and abused boys at the privately run Cambridge House children's care home.
Liberal Democrat President Tim Farron said the party needs to answer "serious questions" about who knew Sir Cyril faced allegations of sexual abuse.
Liberal Democrat leader Nick Clegg last year said the allegations against Sir Cyril should be investigated "to the bitter end".
More top news
In an interview with The Sunday Telegraph David Cameron has set out a series of policies designed to appeal to traditional Tory voters.
Nick Clegg will attempt to win over the female electorate when he kicks off the Liberal Democrats' general election campaign later today.
Up to £140 billion of savings could be released when over 55-year-olds are allowed to cash in their pension pots from April 6th.