Reproductive rights activists weave through a lively crowd outside a concert hall in Orlando, urging young concertgoers to pledge "Yes" to a ballot measure that aims to embed abortion rights into Florida's constitution.

Known as "Amendment 4," the question is expected to appear on the same ballot as the United States presidential vote, aimed at restoring the right to terminate pregnancies until the point of viability in the nation's third most populous state.

Since May, Florida has enforced a ban on abortions after six weeks,which appears that some women might not know they are pregnant.

The initiative faces a steep challenge, requiring 60 percent approval to pass, which is the toughest threshold among ten states holding similar referendums on November 5.

The campaign gathered over a million signatures to qualify for the ballot.

According to the organization that started the campaign, Floridians Protecting Freedom, since its approval in April, more than 6,000 volunteers have been mobilized and $30 million has been raised for the cause.