The final attempt at using economic embargo as a political weapon before the War of 1812 was:

Boycott of the items and products of Britain.

Explanation:

The final attempt at using economic embargo as a political weapon before the War of 1812 was the Boycott of the products of Britain by the people of united states. this act was done to put pressure on the Britain government to lower the taxes but this act did not put pressure on the Britain empire and the taxes was not lowered so for that reason the war of 1812 was by the United states fought against Britain empire.