The anger behind Donald Trump¡¯s firing of FBI Director James Comey on Tuesday had been building for months, but a turning point came when Comey refused to preview for top Trump aides his planned testimony to a Senate panel, White House officials said.

Trump, Attorney General Jeff Sessions and Deputy Attorney General Rod Rosenstein had wanted a heads-up from Comey about what he would say at a May 3 hearing about his handling of an investigation into former Democratic presidential candidate Hillary Clinton¡¯s use of a private email server.

When Comey refused, Trump and his aides considered that an act of insubordination and it was one of the catalysts to Trump¡¯s decision this week to fire the FBI director, the officials said.