Mark Clarke, the “Tatler Tory” accused of bullying young activists, was handed the email addresses of young Conservative members by the party’s central office, raising fresh concerns about the access he was granted by Tory high command.

The revelation will add to the pressure on Lord Feldman, the Conservative chairman and a close personal friend of David Cameron, to step down. Young activists who were party members but had not signed up to RoadTrip2015, the organisation spearheaded by Clarke to campaign in marginal constituencies last May, received a series of emails from Clarke between September 2014 and the general election.

Most of the emails, in which members were encouraged to join campaigning events, were sent from Clarke’s personal email address. One boasted: “We work hard. But we also play hard in the evening.” Feldman says he was unaware of bullying allegations within the youth wing until August this year.

Clarke, 38, a marketing analyst at Unilever who is married with two children, has been accused of creating a wild atmosphere after RoadTrip events and having sex with young members. Clarke also used the emails to encourage members to interact with him on Twitter and Facebook. He has been accused of sending intimidating Facebook messages to young members.

The revelation that Clarke was handed contact details of Conservative members poses questions about the party’s usage of its members’ data. Legal sources told the Observer the party could have breached the Data Protection Act, depending on the extent to which Clarke is judged to have been operating on behalf of Conservative Campaign Headquarters (CCHQ). When signing up online, prospective members are told: “We will not share your details with anyone outside the party.” In addition, if the emails from Clarke were considered to be unsolicited marketing emails, then the Conservatives may have breached the Privacy and Electronic Communications Regulations 2003.

One young Conservative, who did not wish to be named because he feared the repercussions of speaking out against HQ, says he was “astonished” that Clarke had been given his details by central office, and that it “undermines my trust” in the party.

Ray Johnson, the father of the 21-year-old party member Elliott Johnson, who is believed to have killed himself in September after allegedly being bullied by Clarke, has already called for Feldman to resign. Grant Shapps, Feldman’s co-chair until May, resigned from a junior ministerial position last month over his handling of the allegations. Clarke has denied any accusations of bullying.

The party has maintained that it has no record of written complaints that were not dealt with before it launched an investigation into Clarke’s conduct in August. However, Conservative figures have since claimed that party chiefs were aware of concerns about Clarke far earlier than last summer, with Ben Howlett, the Conservative MP for Bath, saying he complained about Clarke’s bullying in 2010 and insisting that Feldman “has been well aware of all this, for a very long period of time”.

Jon Ashworth, the shadow minister without portfolio, said: “Grant Shapps has rightly resigned. Yet Lord Feldman remains in place with serious questions to answer. Surely it’s time for Lord Feldman to come clean about what he knew and when.”

A Conservative spokesperson said: “As he said in his resignation letter, Grant Shapps incorporated RoadTrip into the wider election campaign. There was no data protection breach.”