Thousands of betting shops are opening on Good Friday for the first time since the government relaxed gambling laws last year, prompting criticism from some Christian groups.
Churches said that it was wrong to allow gambling on one of the most important dates in the Christian calendar when millions remember Christ's death on the cross.
"We would encourage operators to keep their shops closed on Good Friday, but those who insist on opening will, we hope, undertake to donate a decent portion of their profits towards programmes of education, research and treatment aimed at checking the growth in problem gambling," the Church of England said in a statement.
Mike Judge, from the Christian Institute, a charity that promotes the Christian faith, told The Daily Telegraph: "To allow gambling and encourage avarice on Good Friday, when we are remembering the sacrifice Jesus made for the world, is particularly regrettable."
Gamblers will be able to bet on foreign horse races, greyhounds and football. Traditionally, race meetings are not held in Britain on Good Friday.
Ladbrokes spokesman Ciaran O'Brien said the change would put bookmakers on the same footing as other shops that have opened their doors on Good Friday for more than a decade.
"I wouldn't want to moralise about how people spend their leisure time," he told BBC radio. "You can bet online any day of the week, any time of the day. That's another reason why the shops should be able to compete."
There are no plans to open betting shops on Christmas Day, he added.
Ladbrokes, one of Britain's biggest chains, said it would open 1,900 of its 2,200 shops, while its rival William Hill will open about 200 stores.
Last September's Gambling Act allowed betting shops to open on Good Friday for the first time. It was previously banned under the Betting and Gaming Act of 1960.
