Member of political party spilling the beans but not initially making false claims

WordNet Word definitions in WordNet
n. a tort consisting of false and malicious publication printed for the purpose of defaming a living person the written statement of a plaintiff explaining the cause of action (the defammation) and any relief he seeks [also: libelling , libelled ]

Wiktionary Word definitions in Wiktionary
vb. (present participle of libel English)

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Libel \Li"bel\, v. t. [imp. & p. p. Libeled (-b[e^]ld) or Libelled ; p. pr. & vb. n. Libeling or Libelling .] To defame, or expose to public hatred, contempt, or ridicule, by a writing, picture, sign, etc.; to lampoon. Some wicked wits have libeled all ...