An investigation into alleged bullying within the Conservatives must bring about a cultural change in the party, the father of a 21-year-old member who apparently took his own life has said.
Elliott Johnson, 21, a member of the Conservative Future youth wing, was found dead on railway tracks in September.
A month earlier he had alleged bullying and his death sparked an investigation and the resignation of former party chairman Grant Shapps.
His father Ray Johnson, from Wisbech, Cambridgeshire, has welcomed the decision to bring in law firm Clifford Chance to conduct the investigation rather than it be carried out in-house.
But he said that, unless new procedures were introduced to prevent similar tragedies, young people may continue to suffer in the same way as his son.
He told the Press Association: "It's got to stop, simple as that. You just cannot have organisations, particularly organisations which are running a country, allowing that kind of endemic bullying to exist.
"Some kind of process needs to be put in place to prevent it in future. Too many young lives have been damaged by this excessive amount of bullying, harassment and intimidation."
The allegations centre on the activities of the former activist Mark Clarke, who has since been expelled from the party. Mr Clarke has strongly denied the allegations against him.
Mr Johnson says that his son's concerns were brought to the party's attention on August 12. Elliott was found dead on railway tracks near Sandy station in Bedfordshire on September 15.
In the weeks leading up to his death he had seemed "happy and normal" as he attended several family weddings and his graduation from Nottingham University, Mr Johnson said.
His parents first became aware of a problem when Elliott told them he had lodged a complaint about an alleged incident in August.
"He just brushed it aside and certainly didn't mention any prior or later bullying," Mr Johnson said.
"He thought it was being handled properly and he just put it behind him.
"He seemed absolutely fine, he was happy and enjoying himself. Nothing gave us the feeling anything was amiss."
It was only after police arrived on their doorstep late on September 15 to break the news their son had been found dead that the extent of the allegations began to emerge.
Mr Johnson said: "It came as a bolt from the blue, we just couldn't think why this had happened.
"Then the police found three letters in his room and he had named two people in one of those.
"It was then that we knew there was something not right. Information came to us from various sources including some of his friends and it was just clear to us that something was really badly wrong.
"We also found out from some of Elliott's friends that it was endemic within Conservative Future and to some extent within Conservative Party headquarters.
"I was shocked to find that level of bullying was tolerated."
Mr Johnson has said the blame should rest with Lord Feldman - an old university friend of David Cameron who was co-chairman with Mr Shapps until the general election in May - and has called for his resignation.
" I'm sure they thought they could sweep us under the carpet the levels of denials or obstruction proved to me that they had no real intention of changing their ways so we just had to keep on pushing and pushing and pushing and eventually the dam broke," he added.
"I'm sure Lord Feldman was aware what was going on because my son made his complaint directly to him and in my mind the tragedy rests on his shoulders.
"Grant Shapps has gone, I'm sure others will go but the man at the top has to take responsibility for his actions or, in this case, inaction."
Mr Johnson added that the inquiry should not be allowed to drag on or be buried: "W hat I don't want is for this to be kicked into the long grass, political parties have a habit of doing things like that."
Pressure has continued to mount despite Mr Shapp's resignation. Downing Street has stressed that Lord Feldman retains the "full confidence" of Prime Minister David Cameron.
Asked about the tragedy last month, Mr Cameron said: "It is a tragic loss of a talented young life.
"It is not something that any parent should have to go through and I feel for them deeply. I feel deeply for his parents."
Clifford Chance LLP has been instructed to prepare a report on the issues raised, with a remit to assess whether complaints were handled properly and "identify any individuals who were at fault".
The firm's lawyers will also consider the integrity of the evidence-collecting process and whether the right people have been interviewed.
The collection of evidence is not expected to be completed until the end of the year, and Clifford Chance will produce the report "as soon as possible after that".
The BBC reported that it had seen a memo sent to Conservative Party officials by a former member of staff at party HQ in August which warned Mr Clarke was "a sociopath" and "dangerous".
The memo, obtained by BBC2's Newsnight, alleged that Mr Clarke's "bullying tactics are well-known... it would literally be impossible to list all his crimes here".
It stated that Mr Johnson's complaint "is the tip of the iceberg. Before the election we knew he (Clarke) was badly behaved but he managed to keep it away from us and under wraps. Since then he appears to be unravelling".