washington three congressional committees scuffle former british spy report central investigations u.s. allegations russia try help donald trump 2016 presidential campaign people involve inquiries say dossier assemble former mi6 officer christopher steele outline russian financial personal link trump campaign associate senate intelligence committee special counsel robert mueller look possible collusion russia trump campaign mueller investigators meet steele however republican chairmen house intelligence senate judiciary committees challenge dossier credibility one imply russians may play role preparation source familiar inquiries say duel purely partisan senator richard burr republican chairman senate intelligence committee mark warner committee rank democrat lead committee members party call serious effort pursue allegations dig steele understand good deal information remain unproven none disproven considerable amount prove democrat sheldon whitehouse member senate judiciary committee say interview reuters elaborate russia repeatedly deny interference last november election businessman trump republican democrat former secretary state hillary clinton trump deny collusion campaign associate report publish january four u.s. intelligence agencies say take dossier allegations seriously senate judiciary committee chairman chuck grassley harsh public critic steele suggest russia might somehow influence fusion gps u.s. opposition research firm hire steele may break u.s. law dossier first commission behalf trump opponents republican primary democrats take trump become presidential nominee steele meet fbi representatives election discuss find march letter then-fbi director jam comey grassley write idea fbi associate clinton campaign would pay mr. steele investigate republican nominee president run-up election raise question fbi independence politics well obama administration use law enforcement intelligence agencies political end whitehouse however say july 27 judiciary committee hear call grassley part republican effort discredit steele create confusion false impression russia pay steele dossier could clear evidence russian role behind steele dossier whitehouse say judiciary committee aide speak condition anonymity say american people need able trust fbi justice department operate free political influence investigation follow facts wherever lead despite recuse april house intelligence committee investigation republican chairman devin nunes also try discredit steele work source familiar probe say tuesday nunes subpoena partner run fusion gps u.s. opposition research firm hire steele source familiar matter say blatant attempt undermine report so-called dossier even core conclusion broad campaign russian government influence outcome 2016 presidential election confirm u.s. intelligence community widely accept fact joshua levy counsel fusion gps say statement committee democrat eric swalwell also fire back say nunes tell congress recuse issue subpoena would violate recusal also way go alone work democrats look like try undermine investigation swalwell say nunes also use power last month issue subpoena fbi justice department fbi director christopher wray deputy attorney general rod rosenstein demand surrender file steele dossier investigations work far justice department fbi turn information nunes request fbi investigation supervise special counsel mueller mueller office decline comment request investigation u.s. congressional panel spar 'trump dossier russia contact