If a petition protesting the annexation of an area under this subchapter is signed by a number of registered voters of the municipality proposing the annexation equal to at least 50 percent of the number of voters who voted in the most recent municipal election and is received by the secretary of the municipality before the date the petition period prescribed by § 43.0685 ends, the municipality may not complete the annexation of the area without approval of a majority of the voters of the municipality voting at an election called and held for that purpose.