London, England (CNN) -- Posters calling for the ordination of female priests will be plastered on London buses next month during the pope's visit to Britain, a campaign group said Friday.
The ads read "Pope Benedict -- Ordain Women Now!" and will be on 15 double-decker buses running in some of London's main tourist areas, including Parliament and Oxford Street, said Pat Brown, a spokeswoman for Catholic Women's Ordination (CWO).
The group hopes the ads will raise awareness of the group and the issue, she said.
"The idea of the bus is really to draw people to us as an organization and to let people know that we're out there," she told CNN.
The group spent "in excess of 10,000 pounds" ($15,500) on the ads and is hoping donations will help make up at least part of that cost, Brown said.
"This is an absolute one-off," she said. "We've spent all our money, literally, so we're hoping to get some back."
Pope John Paul II declared in 1994 that the church has no authority to ordain women, a position confirmed a year later by Cardinal Joseph Ratzinger, who is now Pope Benedict XVI, but was then the head of the Congregation for the Doctrine of the Faith.
The declarations make discussion of the issue of women's ordination off-limits within the church, Brown said, and that limits awareness of the CWO and the issue it promotes.
"We often meet people who say, 'I didn't know you exist,'" she said. "They don't know we exist, they don't know that this issue is being discussed."
In addition to the bus campaign, CWO plans to hold a vigil Sept. 15, the day before the pope's visit, outside Westminster Cathedral.
They also plan to demonstrate at Lambeth Palace, the official London residence of the Archbishop of Canterbury, when the pope meets with the head of the Anglican church there, and they plan to hold a banner along the route of the popemobile, the secure vehicle which carries the pope, in London.
Pope Benedict plans to visit England and Scotland from September 16 to 19. It will be the first state visit to the United Kingdom by a pope, according to the British Foreign Office because John Paul's trip in 1982 was officially a pastoral visit.