is all just hearsay and nothing directly connected to the president. >> come to order. >> reporter: the first day of public impeachment hearings beginning with a startling revelation for investigators. top diplomat to ukraine bill taylor describing a phone call between president trump and the u.s. ambassador to the european union gordon sondland. overheard by his aide one day after the july 25th phone call with the ukrainian president. >> mr. sondland told president trump the ukrainians were ready to move forward. following the call with president trump, my staff asked what president trump thought about ukraine. sondland responded that president trump cares more about the investigations of biden which giuliani was pressing for. >> reporter: trump denying that call. >> i know nothing about that. first time i've heard it. >> reporter: but house democrats says this helps make their case that trump abused his oath of office even stronger.