washington two former u.s. officials intelligence director jam clapper deputy attorney general sally yates testify next month congressional investigation allege russian meddle 2016 u.s. presidential election senate judiciary committee say tuesday congressional committees begin investigate issue u.s. intelligence agencies conclude russian president vladimir putin order hack democratic political group try sway election toward republican donald trump moscow deny meddle clapper former director national intelligence yates former deputy attorney general testify may judiciary committee subcommittee crime terrorism judiciary chairman charles grassley say statement witness may add senate democratic leader chuck schumer say tuesday little trouble senate intelligence investigation appear move slowly reuters report monday probe senate main investigation allegations russian election meddle much small staff previous high-profile congressional investigations clapper yates another official also serve former president barack obama ex-cia director jam brennan schedule testify house representatives intelligence committee march hear cancel panel chairman republican devin nunes nunes trump ally recuse russia investigation april receive information intelligence agency surveillance foreign nationals sweep information members trump transition team decision hold news conference discuss information trump disclose democrats raise question whether could lead credible investigation house committee friday invite yates clapper brennan appear public hear schedule may 2. judiciary subcommittee chairman republican lindsay graham say want ask clapper yates whether know court order allow fbi surveillance communications trump campaign adviser carter page 2016. washington post report month warrant issue clapper say march television interview aware wiretapping trump advisers want get bottom graham say fox news former u.s. officials testify may senate hear russia probe