THE growing scandal over alleged bullying, sexual abuse and blackmail in the Conservative party’s youth wing yesterday led to the dramatic resignation of a government minister.

Grant Shapps quit as international development minister after failing to act, in his previous role as party co-chairman, over allegations of bullying by youth organiser Mark Clarke.

His departure came just a day after the father of a Tory activist allegedly driven to suicide by bullying called for Shapps and current chairman Lord Feldman to resign.

Ray Johnson said his son Elliott, who was 21 when his body was found on railway tracks in Bedfordshire in September, would still be alive if Shapps and Feldman has acted properly.

A note left by Johnson, a blogger for a Tory pressure group, named Clarke as a bully.

Ray Johnson welcomed Shapps's resignation. "It's about time, he should have resigned several weeks ago," he said.

With the spotlight now likely to turn on Lord Feldman, a key Cameron ally, Downing Street insisted the peer retained the Prime Minister's “full confidence".

A Tory election candidate in Tooting in 2010, Clarke, 38, was banned from the Conservative party for life last week, but denies any wrongdoing.

"I believe that these false allegations and this media firestorm are related to the events surrounding Elliott's sad death," he said.

"As such I will be co-operating with the coroner [examining Johnson’s death] and providing him with the fullest information. This is the proper process. After the inquest I will look to take legal action for defamation in respect of these allegations."

Shapps appointed Clarke director of RoadTrip 2015, which bussed young Tories to key seats in the general election, despite him being struck off a list of approved candidates in 2010 following complaints of “aggressive” behaviour and concerns over his private life.

In his resignation letter to David Cameron, Shapps said: "Although neither the party nor I can find any record of written allegations of bullying, sexual abuse or blackmail made to the chairman's office prior to the election, I cannot help but feel that the steady stream of those who raised smaller, more nuanced, objections should have perhaps set alarm bells ringing sooner.

"In the end, I signed that letter appointing Mark Clarke 'director of Road Trip...Over the past few weeks - as individual allegations have come to light - I have come to the conclusion that the buck should stop with me."

Shapps admitted he gave Clarke a "second chance" after he was removed from the party's candidate list, adding: "He presented himself as having learned from his past experience, being more mature and wanting to prove himself again.”

Shapps said the Johnson family's loss was "simply unimaginable", adding: “More than anything, I am deeply shocked and saddened by the recent death of Elliott Johnson and my thoughts are with his friends and family.”

Since Johnson’s death, around two dozen Tory activists are understood to have complained about bullying and sleaze on Roadtrip 2015, as well as a blackmail plot against a Tory MP.

The party had initially denied knowing about complaints against Clarke until August.

However on Friday, Shapps’s predecessor as party chair, Baroness Warsi, said she had raised his behaviour with Shapps by letter in January, accusing him of trolling her on Twitter.

“I look forward to hearing from you what action you intend to take against Clarke,” it said.

The peer said she had never received a “satisfactory response” from Shapps, even though it was “common knowledge” that Clarke was “a disaster waiting to happen”.

Speaking in Malta, the Prime Minister said Johnson's death had been a "tragic loss" and a "proper inquiry" was being held into the allegations overseen by an independent lawyer.

"I feel deeply for his parents. It is an appalling loss to suffer," he 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."

In his letter accepting the resignation, Cameron told Shapps: “I understand your reasons for stepping down and accept your decision", but added he would "always remember" that he had been "a loyal and trusted supporter of mine from the very beginning".

Shapps is replaced at international development by Big Society minister Nick Hurd.