The Conservative Party chairman and a minister should resign over allegations they failed to act on claims of bullying within the party's youth wing, the father of an activist who killed himself has said.
Ray Johnson claimed his 21-year-old son Elliott would still be alive if Lord Feldman and Grant Shapps had behaved "responsibly".
The party has said it was not aware of any complaints against Mark Clarke, who ran the party's "Road Trip" operation during the general election campaign, until August.
He has since been expelled over bullying and blackmail allegations, but denies any wrongdoing.
Former Conservative Party chairman Baroness Warsi has disclosed that she sent Mr Shapps a letter, dated January 20 this year, accusing Mr Clarke of publicly abusing her on Twitter. "I look forward to hearing from you as to what action you intend to take against Mr Clarke," it said.
The peer told the Guardian she never received a "satisfactory response" to her complaint, even though it was "common knowledge" that Mr Clarke was "a disaster waiting to happen".
She said: "During my time as chairman, Mark Clarke was never involved in any initiative that I was involved in or in any campaigning. He was effectively persona non grata, as far as I was concerned."
Mr Johnson, whose son was found dead on railway tracks in September and is thought to have left a note condemning Mr Clarke, told the newspaper: "They need to stand down. Feldman, Shapps and whoever else is involved in this...
"You wonder about the people running the country - whether they're fit to govern. If they had behaved responsibly like any other organisation, none of these events would have happened; my son would be alive and many activists wouldn't have been intimidated and harassed."
A Tory spokesman said: "An investigation is currently under way and it is not appropriate to comment until we can establish the facts."