lip service

Verbal expression of agreement or allegiance, unsupported by real conviction or action; hypocritical respect: “Lip service continues to be paid to resolving regional conflicts, but there is no sense of urgency” (Henry A. Kissinger).

Verbal but insincere expression of agreement or support. It is often put as pay or give lip service, as in They paid lip service to holding an election next year, but they had no intention of doing so. [Mid-1600s]

The noun has one meaning:

Meaning #1: an expression of agreement that is not supported by real conviction
  Synonym: hypocrisy