SNP activists gathering next weekend will be told continued membership of Nato will prevent Scotland getting rid of nuclear weapons.
The party leadership is facing a full-scale rebellion at National Conference in October and next weekend's meeting of the CND group within the party is turning into a rallying point for dissent on the issue.
A strategy document for the meeting in Glasgow seen by The Herald cites the examples of Germany, the Netherlands and Belgium – all of which have voted to remove nuclear weapons from their soil, only to be thwarted by Nato.
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The paper argues the policy change of the SNP to back continued membership of Nato could cost the SNP its vision of Scotland as a "young, vibrant and peaceful proposition".
The SNP said an independent Scotland could remain in Nato but remain opposed to nuclear weapons.
However, the CND group will claim the policy is likely to "put off those who support a peaceful prospectus but is unlikely to do much for people who like guns and bombs" while making the SNP "look cynical and lacking in moral courage".
The report concludes: "It alienates almost all active supporters of independence outside the SNP and will cause more conflict within the Yes campaign."
The party's Westminster leader and defence spokesman Angus Robertson MP believes a pledge of continuing membership of Nato will be another reassuring pitch in appealing to Scots voters in the 2014 referendum, arguing Norway is both a non-nuclear state and member of the alliance.
But opponents of the change point out Norway has never been a nuclear state, unlike Scotland which already has nuclear weapons on its territory.
Nato is also likely to resist the move as it would leave the UK without any nuclear weapons, the report added.
The document stated: "The proposal to change SNP policy may be well-intentioned, but it fails to take account of the reality of Nato politics.
"The question would be lost in the byzantine decision-making process of the alliance. Several members of Nato, including the RUK (Rest of the UK) and the US, would be keen to postpone any answer.
"Their goal would be to retain Scotland within the alliance, with Trident still at Faslane."
The Herald earlier reported that Alex Salmond is facing a growing revolt over plans to drop the SNP's historic opposition to Nato, with at least seven MSPs now throwing their weight behind a campaign to keep the policy. A further two are understood to be in discussion with their constituency parties over the move.
Next weekend, the SNP activists will argue the experiences of Germany, Belgium and the Netherlands should provide a "clear warning" to Scotland.
"These are three of the five countries who are hosts to a total of 180 US nuclear weapons," the report added. "The SNP has sold an independent Scotland as a young, vibrant and peaceful proposition. It is proposing a change that confuses that proposition."
An SNP spokesman said previously: "The SNP has a cast-iron commitment to rid Scotland of nuclear weapons. Given the continued presence of Trident nuclear weapons in Scotland – against the wishes of her Parliament and people – independence is the only constitutional option which makes this possible.
"SNP members have the democratic opportunity to make their views on Nato membership clear at the annual conference in October, where we expect to have an excellent debate."