The founder of electric truck maker Nikola, convicted last year of defrauding investors about his company’s technology, now is suing his legal chief and other insiders, saying they praised him for aggressively promoting the company before turning on him when scrutiny of the business increased.

Trevor Milton, who in December was sentenced to four years in prison, says in the June 6 lawsuit that he relied heavily on Chief Legal Officer Britton Worthen, who also was his personal attorney, to advise him on what he should or shouldn’t say on social media and in other public forums about the Phoenix-based company.