The Church of England has accused the National Trust of 'airbrushing faith' after dropping the word 'Easter' from its annual Easter egg hunt.
The row came as it emerged that the National Trust and Cadbury are to hold more than 300 'alternative' Good Friday events this year.
The Good Friday egg hunts will take place from 10-4pm on the most solemn day of the Christian calendar.
The annual hunt, in which hundreds of thousands of children search for chocolate eggs at National Trust properties, has been rebranded to exclude Easter for the first time in 10 years.
In previous years it has been called an 'Easter Egg Trail', but this year it is renamed as the 'Great British Egg Hunt'.
The National Trust Easter hunts began in 2008 as small events for families on Easter Day and the Easter Monday Bank Holiday. Now they are set to become major four-day events, starting on Good Friday, with more than a million families targeted and 380,000 children expected to attend.
Cadbury said that it wanted to appeal to non-Christians. 'We invite people from all faiths and none to enjoy our seasonal treats,' it said.
But a spokesperson for the Church of England said: 'This marketing campaign highlights the folly in airbrushing faith from Easter.'
The Archbishop of York, John Sentamu, said the decision to remove the word Easter from the egg hunt amounted to 'spitting on the grave' of John Cadbury, the chocolate firm's original founder, a Quaker industrialist.
David Marshall, who heads the Meaningful Chocolate Company, said: 'As the manufacturer of The Real Easter Egg, the UK's only religious Easter egg, we are really shocked to see a rival to Good Friday being set up. This is an industrial operation to effectively replace Jesus with the Cadbury bunny and lure children and families away from Good Friday traditions.'
Marshall told Christian Today: 'Running an alternative to Good Friday - you can't get a stronger signal of an attitude to faith than that.'
The National Trust website invites people to 'Join the Cadbury Egg hunt at the National Trust', having previously said: 'National Trust Easter Egg Trail Supported by Cadbury'.
The National Trust denied that it was downplaying Easter and said that Cadbury was responsible for the rebranding of the egg hunt.
A spokesperson said: 'The National Trust is in no way downplaying the significance of Easter, which is why we put on a huge number of events, activities and walks to bring families together at this time of year. We work closely with Cadbury, who are responsible for the branding and wording of our egg hunt campaign.'
In a subsequent statement, a National Trust spokesman said: 'It's nonsense to suggest the National Trust is downplaying the significance of Easter. Nothing could be further from the truth. We host a huge programme of events, activities and walks to bring families together to celebrate this very special time of year.
'A casual glance at our website will see dozens of references to Easter throughout. Our Easter events include our partnership with Cadbury, which has been running Easter Egg Hunts with us for 10 years. They've proved consistently popular with our members and visitors. As part of its wider marketing activity at Easter, Cadbury will always lead on the branding and wording for its campaigns.'
The National Trust added in a Tweet: "We are not downplaying the importance of Easter in any way, with [more than] 13,000 mentions on our website alone.'
A spokesperson for Cadbury said: 'Each year, our Easter campaigns have a different name and this year our seasonal campaign is called the 'Cadbury's Great British Egg Hunt'.
'It is clear to see that within our communications and marketing we clearly state the word Easter and include it in a number of promotional materials, including our website, where we do also promote our partnership with National Trust at this seasonal time of year. We invite people from all faiths and none to enjoy our seasonal treats, which can be found around Easter time.'
Last year Cadbury faced a backlash from customers over the disappearance of the word 'Easter' from the front of its Easter egg packaging. The product was labelled 'Milk Chocolate Eggs' and the word 'Easter' featured only on the back of packaging.