Dr Rowan Williams is due to speak as the Church's national assembly gathers after the legislation failed to gain the necessary two thirds majority amongst lay members.
His statement will come after an emergency meeting of the Church of England bishops following the narrow defeat.
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The Bishop of Salisbury has called the attack on Segei Skripal and his daughter Yulia "a violation of our community."
Thursday night's weather for the west of the region
Thursday night's weather for the east of the region