Archbishop Vincent Nichols, who will take over as the head of the Catholic Church of England and Wales next month, warned Friday against relaxing rules on broadcasting abortion and condom adverts.
In an interview with the Press Association news agency, the 63-year-old urged the country's five million Catholics to respond to a public consultation on the proposed changes, saying adverts should be "truthful and tasteful".
"I doubt that any intended adverts about abortion would be fully truthful and tell the whole truth of the effects of abortion in a woman's life," he said of plans to allow pregnancy advisory services to advertise on radio and TV.
He added: "It will no doubt be presented as a simple solution. But in fact it has traumatic implications in women's lives. Surely you would not expect it to be advertised alongside a packet of crisps?"
As part of a shake-up of advertising rules, ad watchdogs have proposed allowing pregnancy advisory services, including ones that offer abortion services, to screen prime time broadcast adverts.
They also want to allow condom ads -- which can currently only be broadcast on major channels after 9.00 pm, when an adult audience is presumed -- at any time of the day, except around programmes targeted at children under 10.
"I seriously wonder if any advertisements for the use of condoms would be tasteful because the ones we have at the moment are demeaning of the young people of this country," Nichols said.
"They depict casual sex on the street corner and drunken sex. I do not think these things do anything to genuinely help young people to understand themselves."
The Vatican last week named Nichols, a champion of traditional Catholic values, to replace Cardinal Cormac Murphy-O'Connor as archbishop of Westminster.