Christians are asking the Dean of Westminster Abbey to "urgently reconsider" hosting a service of thanksgiving for 50 years of Britain's nuclear deterrent at sea.
A statement has been signed by nearly 200 Anglican clergy ahead of the service, organised by the Royal Navy, on Friday.
It says that the service is at odds with the Church of England's promise at its 2018 General Synod to "work tirelessly" towards the elimination of nuclear weapons.
The Campaign for Nuclear Disarmament said it would hold protests outside the Abbey if the service goes ahead as scheduled.
The service at noon on Friday is described by Abbey officials as an occasion to "recognise the commitment of the Royal Navy to effective peace-keeping through the deterrent over the past fifty years and to pray for peace throughout the world".
The Abbey has not commented on the protests, which the CND said would include a 'die-in' to represent the victims of nuclear warfare.
Kate Hudson, general secretary of Christian CND, which coordinated the statement, said: "Surely Westminster Abbey must now realise it has made a very serious error of judgement.
"The Abbey should listen to these members of the clergy and listen as well to the thousands of members of the public who have written to the Dean to make clear what ought to be obvious, that nuclear weapons should not be celebrated.
"Listen to members of the House of Lords who, in a report out this week, said the threat of nuclear war is dramatically rising. Every level of church, government and society should be engaged in efforts to de-escalate nuclear tensions. A thanksgiving service to honour nuclear weapons is absolutely the last thing we need.
"We say to the Dean, it is not too late to cancel the service. It's right to cancel it, and millions would respect the church for having listened and taken action to correct a mistake."
