Elliott Johnson wrote letters, found after his death, in which he claimed he was bullied by Tory supporters.
His parents want his inquest to be widened to include evidence about the culture in the Conservative Party.
A pre-inquest review has taken place to hear from lawyers on both sides.
An extract from one of the letters was read to Ampthill Coroner's Court, near Milton Keynes.
The 21-year-old wrote: "These past few weeks have been the most difficult of my life. I've failed in money, failed in life, failed in politics."
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Heather Williams QC, representing Mr Johnson's parents Alison and Ray Johnson, said the treatment he received could be considered "inhuman or degrading".
"The family believe his death was directly linked to a series of events that occurred in the last few weeks of his life," she added.
Mr Johnson made a complaint about bullying weeks before he was found dead in Bedfordshire.
The case subsequently led to the resignation of former party co-chairman Grant Shapps.
Former activist Mark Clarke, who is at the centre of the allegations, which he denies, has been expelled from the party.
June 2015:  He starts working for the campaign group Conservative Way Forward as political editor.
12 August: Mr Johnson makes a complaint to the Conservative party about activist Mark Clarke. Around the same time he is demoted due to budget cuts.
5 September: He withdraws his complaint after a meeting with Mr Clarke.
15 September: Mr Johnson is found dead on railway tracks near Sandy station, Bedfordshire.
16 September: Police find a letter in his room accusing Mr Clarke of bullying. He denies this allegation.
18 November: Mr Clarke is expelled from the party.
28 November: Grant Shapps resigns amid claims he failed to act on bullying complaints while he was co-party chairman.
George Alliott, representing Mr Johnson's former employer, the campaign group Conservative Way Forward, said a more in-depth inquest would "have to include reference to Elliott's mental health and his sexuality".
Mr Johnson's parents, who live in Wisbech, Cambridgeshire, have decided not to participate in an internal review by the Conservative Party saying they fear it will be a whitewash.
Coroner Tom Osborne will deliver his written decision on what evidence will be heard at the full inquest later this week.
A young Conservative activist found dead on railway tracks could have suffered "inhuman or degrading" treatment at the hands of party members, a hearing has been told.