A builder has accused the construction union of blackmail, insisting he lost job contracts in the ACT after refusing to pay them "bribes".

Claw Constructions owner Troy Armstrong labelled the CFMEU thugs and liars in his witness statement to the royal commission into union corruption. He says union organiser Tony Vitler warned him in 2012 that he would not win jobs if he didn’t sign an enterprise bargaining agreement with the union, or…