The first phase campaign was done under the slogan "Con Z de Zapatero" (With Z of Zapatero), a joke based on the Prime Minister and socialist candidate's habit of tending to pronounce words ending with D as if they ended with Z.
IU chose the pre-campaign slogan "LlamazarES + Más Izquierda" (LlamazarES (is) More Left), calling attention to their position as the third national party.