First Minister Alex Salmond will lead calls to scrap the Trident nuclear programme at a major rally in the capital.
Hundreds of people are expected to gather in Edinburgh for the Cut Trident Not Jobs march organised by anti-nuclear campaigners.
Mr Salmond, joined by trade union and Church of Scotland representatives, will appeal to the UK Government to drop multi-billion pound plans to replace the Trident nuclear submarine system currently based at Faslane on the Clyde.