influence peddling

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

• noun The practice of using one's influence with persons in authority to obtain favors or preferential treatment for another, usually in return for payment.

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

• noun a type of corruption in which people use their connections with governments to gain favors or preferential treatment for a third party, usually in return for money.