hot line

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A direct and immediate telephone linkup, especially between heads of government, as for use in a crisis.
2. n. A telephone line that gives quick and direct access to a source of information or help: "This 24-hour hot line has . . . volunteers on duty to talk to callers about personal problems” ( New York).

Wiktionary

1. n. alternative spelling of hotline.

WordNet 3.0

1. n. a direct telephone line between two officials