David Cameron has said his promise to make devolution work better for Scotland is not a consolation prize for Alex Salmond if the nation votes to stay as part of the UK.
Mr Cameron was addressing his Scottish party members at the Edinburgh International Conference Centre.
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Five people were killed and dozens more were injured after a car and knife attack in the capital on Wednesday afternoon.
Among those expected to attend the ceremony will be former US President Bill Clinton and ex-Northern Ireland first minister Peter Robinson.
Five people have been killed and 40 injured after a car and knife attack in London on Wednesday.