The event, which will be held in Stirling on Saturday and clashes with the nearby Battle of Bannockburn 700th anniversary commemorations, is promoted as an opportunity to celebrate and recognise the bravery and skill of members of the UK military past and present.
But the Scottish Peace Network - a collection of around 30 groups including the Scottish CND, the Edinburgh Stop the War coalition and the Women's International League for Peace and Freedom - have said the event promotes weaponry designed to maim and kill and the idea that war is "necessary and desirable".
Brian Larkin, a spokesman for the Scottish Peace Network and co-ordinator of the Edinburgh Peace and Justice Centre, said he expected around 50 opponents to turn out at the protest. He said: "We should not be glorifying war. It's disturbing that at Armed Forces Day events weapons that tear human flesh apart are put into the hands of children so that they can play with them."
The Herald revealed yesterday taxpayers will pay more than three-quarters of the £524,000 cost of the event.
A spokesman for the Ministry of Defence said the event was a national occasion for the public to show their support for the UK Armed Forces' "outstanding contribution to this country".