Priority: Tuchanka is a major cut off point, completion of this mission will unlock Priority: The Citadel (part 2), which will result in the Citadel getting attacked by Cerberus.

When should you attack Cerberus Mass Effect 3?

You can do it at any point where galactic readiness is 50%. Everything else just contributes to odds of success and what ending you will get.

Is attacking Cerberus base the last mission?

Mar 19, 2012 · Mass Effect 3 Cerberus Headquarters is the first mission of the third and final ME 3 act. Priority: Cerberus Headquarters is a mission that must be completed in order to access Priority: Earth. It follows the events of the previous missions, and brings Shepard and his crew to Cronos Station.