Protests were to be held outside Westminster Abbey on Friday in opposition to a service taking place to mark 50 years of Britain's nuclear deterrent at sea.

The protest is being organised by the Campaign for Nuclear Disarmament (CND) and will include a 'die-in' to represent the people killed by nuclear weapons. 

Members of Christian CND will be among those taking part when the protest is staged during the noon service, which has been organised by the Royal Navy. 

Kate Hudson, general secretary of Christian CND, called the service 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," she said.

"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."

The Abbey said the invitation-only service was being held 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".

Nearly 200 Anglican clergy have signed a statement organised by the CND urging the Abbey to "urgently reconsider" hosting the service. 

The statement said that the service contradicted the commitment made by the Church of England General Synod last year to work towards eliminating nuclear weapons. 

Ben Ryan, head of research at the Theos think tank, has also spoken in opposition to the service.

"I can appreciate the difficulty this all presents for an Established Church which does not want to be at odds with the Royal Navy, or indeed the government since the Minister of Defence is expected to be present," he said.

"Equally, it seems to me there is little point in being an Established Church if you can't stand your ground on matters of essential faith and morality. If you can't even tell the state that you won't celebrate nuclear weapons, what chance is there to be an authentic moral voice elsewhere?"