As early as 1651, the English government had sought to regulate trade in the American colonies. On October 9, 1651, they passed the Navigation Acts to pursue a mercantilist policy intended to ensure that trade enriched Great Britain but prohibited trade with any other nations. Parliament also passed the Sugar Act, decreasing the existing customs duties on sugar and molasses but providing stricter measures of enforcement and collection. That same year, Grenville proposed direct taxes on the colonies to raise revenue, but he delayed action to see whether the colonies would propose some way to raise the revenue themselves.