Grant Shapps tried to ride out the storm naively thinking it would go away. But a young man had died and something had to give

One man does not create a culture. Mark Clarke is the fall guy but he had friends and associates in high places

Elliott Johnson is believed to have killed himself after making bullying allegations against Mark Clarke

For weeks a steady drip of revelations had challenged the Conservative Party’s insistence that it had no idea about the extent of Mark Clarke’s alleged bullying. This weekend that drip - which the party seemed to dismiss as a distraction - became a deafening torrent and a former party chairman and government minister has resigned.

Hours earlier, the Prime Minister’s admission that he had concerns about the scandal, and his refusal to defend Grant Shapps, was the first meaningful response from a senior Tory since the start of this sorry affair.

And it shames the party that this has taken so long because this is not a story about boorish behaviour, sex on pool tables, or a desperate attempt to revive a party’s grassroots. It is about the wellbeing of young aspiring politicians and activists and the life of Elliott Johnson, a 21-year-old who accused Clarke and others of bullying in an apparent suicide note he left for his parents.

I have spoken to several young activists while covering the story and many have still been too scared to speak out. They talk of a toxic culture - what the new MP Ben Howlett described as institutionalised bullying in one of the bravest and most important interventions in this case.

And one man does not create a culture. Clarke is the fall guy but he had friends and associates in high places. Shapps appointed him to direct the Road Trip 2015 campaign, a vehicle for much of his alleged wrongdoing - all of which he strongly denies - but Baroness Pidding chaired Road Trip and was a key ally. She has declined to comment so far but remains under big pressure.

Grant Shapps, left, and Mark Clarke, bottom right, during the 2014 Tory conference (PA)

Andre Walker, a journalist and former friend of Mr Johnson’s, was recorded apparently 'pressuring' him in a tape he made before his death. He also denies wrongdoing but was part of a circle around Clarke who also have questions to answer, including some journalists with impeccable contacts now reporting on their former friend’s downfall.

Lord Feldman, Shapps’ replacement as party chair, says he knew nothing before August this year, but will have to prove that to the party’s judge-led inquiry. As must Mr Cameron himself, who, as this newspaper revealed, invited Clarke and co to his Chequers country house for a tea party that had been due to take place as recently as last month.

So while it seemed Shapps had to go, if the Conservative Party hoped this scandal would go away, it would be even more naive to think that it ends today. And ultimately all those who were involved in the culture so many have described – or allowed it to continue unchecked – owe it to Mr Johnson and his family to examine their consciences.