Spain's May 15th Movement, which was behind massive mobilizations earlier this year to denounce austerity policies and demand "real democracy," took to the streets of Madrid on Sunday, a week ahead of the general elections, to call for a new social, economic and political model.

Protesters carrying banners and shouting slogans started the march at the Ronda de Atocha.

May 15th Movement members said the protest was not about swaying voters toward any party but about "strong criticism of the current system, as well as a proposal for changing the model."

"We have a serious problem in Spain, since we hold the view that we have already been taken control of even though they don't want to tell us," Democracia Real Ya spokesman Miguel Angel Valencia said.

The march was set to end at the Puerta del Sol, where the movement was born in the spring.

Protesters spent a month camped out at Madrid's downtown Puerta del Sol plaza, inspiring similar protests across Spain to demand "real democracy," as well as social and political change.

The protesters participating in Sunday's march plan to take part in a social forum, where they will debate proposals made by citizens via different initiatives.

About 300 people held an assembly Saturday in the northeastern city of Barcelona, where they agreed to camp out next weekend in the Plaza Cataluña while the general elections are taking place.