Defying a warning by their leader, Alex Salmond, delegates voted by a clear majority to hold a referendum on whether or not to retain the Monarch as head of state for Scotland within the first term of an independent parliament.
An attempt by the party leadership to get the referendum proposal shelved - by remitting it back to the executive - was defeated by 177 votes to 164. However, Mr Salmond was spared a double embarrassment when an amendment committing the SNP to campaign for an elected head of state was defeated by 208 votes to 152.
Roseanna Cunningham, MP for Perth and Kinross and the party's self-proclaimed "Republican Rose", said the SNP was lagging behind the public in the monarchy debate.
Most people believed the SNP already was a republican party and as a matter of "political honesty" it should say so, she argued.
Mindful of the residual affection for the Royal Family, particularly among older voters, SNP policy retains the Queen as head of state while she is resident in Scotland. For most of the year her constitutional functions would be exercised by the Chancellor, or Speaker, of the Edinburgh Parliament.
But while a majority of delegates reluctantly accepted Mr Salmond's logic, that the party risked facing in two directions if it voted to campaign against a monarchy, the loudest applause in the lively debate were for the republicans.
Paul Scott, a party vice-president, said an hereditary monarchy was an insult to human intelligence. "It invites us to treat ordinary human beings as if they were demigods. This is absurd. The real fear of the people who are opposed to this is that it will lose votes. But we are more likely to gain votes if we are intellectually honest."
Putting his authority on the line by speaking in the debate, Mr Salmond sided with those who believed the goal of independence would be jeopardised by a commitment to campaign against the monarchy.
Quoting a former leader, Willie Wolfe, at an earlier high point in SNP history, he said the party's cup "runneth over. Let's show Scotland we can hold it with a steady hand".Reuse content