party line

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun One or more of the policies or principles of a political party to which loyal members are expected to adhere.
• noun A telephone circuit connecting two or more subscribers with the same exchange.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A single telephone line which is shared by two or more households.
• noun The official policy of a political party or other organization.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the policy of a political group
• noun a telephone line serving two or more subscribers