GENEVA (AP) — Swiss capital punishment advocates withdrew their campaign to reinstate the death penalty Wednesday, a day after receiving government permission to collect signatures for a referendum.

The "Committee for the Death Penalty" had proposed reinstating capital punishment for murders involving sexual abuse, almost 70 years after it was abolished in Switzerland. Local media reported that some members of the group were relatives of a 28-year-old woman who was murdered last year.

On its website, the committee said it launched the campaign because it believes Swiss law unfairly favors perpetrators over the victims and their families.

"The campaign was the only legal way for us to make our voices heard," it wrote. "Our main aim was to make the population aware of the problem."

It gave no reason for abruptly terminating the campaign. Efforts to reach the group by telephone and e-mail went unanswered.

Under Switzerland's unique system of direct democracy, citizens can call for a referendum on almost any subject if they collect at least 100,000 signatures. Few, however, face the kind of broad criticism that the death penalty proposal received when it was announced earlier this month.

Authorities said this week that capital punishment could breach the Swiss constitution or international treaties, and that parliament might have moved to block any referendum from taking place.

Had it gone ahead, the ballot would have been the most politically sensitive since Swiss voters decided last year to ban minaret construction.