Supporters of Scottish independence must accept there is no "quick fix" to achieving their goal, a former SNP spin doctor has warned.
Kevin Pringle, who served as the party's media chief under Alex Salmond, said the Union could only be ended if it became the "consistently majority position in Scotland".
Nicola Sturgeon plans to hold a second referendum on independence on October 19 next year - but only if the UK Supreme Court rules her government has the powers to do so.
Opinion polls consistently show Scots are split down the middle on the big constitutional question.
Pringle left the SNP high command in 2015 having worked on the party's succesful breakthrough to power in 2007 and its subsequent Holyrood election win in 2011.
Writing in the Sunday Times, he argued the independence campaign needed "structure, so that all those who wish to be involved can play in the most effective position".
And he cautioned against Yes supporters who believe the First Minister is not working fast enough to achieve her ultimate goal.
Pringle said: "People who are itching to vote "yes" in a referendum next year have to accept that it could be a longer haul rather than a quick fix.
"Timescale and process are important, but the primary business if independence is ever to be achieved is building support to a consistently majority position in Scotland. That is what Yes activists need to focus on.
"It is inevitable and democratic that everyone who wants an independent Scotland has a view about what Sturgeon should or shouldn't be doing, just as many football fans don't hesitate in telling the manager how to do their job, usually in blunt terms.
"However, what the independence campaign needs is a structure, so that all those who wish to be involved can play in the most effective and appropriate position.
"There is a job of leadership to deliver such a plan, but we only need one person being first minister."
He added: "Patience may not be a political virtue as practised in the social media age, but it remains necessary for the Yes side.
"By contrast, politicians who back the Union need to be alive to the dangers of blocking the point of decision until such time as independence has an unassailable lead.
"That was certainly the devolution experience."
