A top strategist in the campaign for an independent Scotland has questioned whether the country would "want or need" an SNP after a Yes vote in the 2014 referendum.

Stephen Noon, who has worked for the Scottish National Party for much of the last two decades, argued that a vote in favour of independence would free Scotland from the 50-year-old constitutional question, paving the way for a "fresh start" for the country and its politics.

Mr Noon, the chief strategist of the Yes Scotland campaign, described a "new world" after such a vote, in which traditional dividing lines would be erased and SNP supporters could give their backing at the ballot box to Labour, and vice versa.

In an essay, he also talked of a new political landscape beyond 2014 with a "multitude of coalition choices", including a "currently inconceivable" Labour and SNP partnership.

Writing in the Scotland on Sunday, Mr Noon said he has worked for the SNP for most of the past 18 years, but it was only in 2007 that it became the party he had voted for most often.

The former floating voter joined the party because of his belief that gaining independence is "essential if we are to create a more successful and fairer Scotland".

He said: "But, after a Yes vote in 2014, that position is transformed. In 2016, Scottish politics will be freed from the constitutional question. The issue that has dominated political discourse for at least 50 years will be no more.

"In this new world, with the most significant dividing line in Scottish politics erased, independence-focused SNP-ers could safely choose to give one or even both their votes to Labour (or Green or Lib Dem), and Unionist Labouristas could happily give one or both votes to the SNP.

"While for some this thought will have them spluttering into their porridge, most of us will recognise this as a real opportunity for a fresh start for Scottish politics, and for Scotland."

Mr Noon argued Scotland's new direction could be truly mapped out with the first election to an independent Scottish Parliament in 2016.

He said: "Think about it for a minute and explore what will be a new political landscape. Who will be leading Labour? It could be one of their current MPs, raising the prospect of a future First Minister Alexander (or Curran or Murphy) rather than a First Minister Lamont. A Labour Party, for once fielding its strongest team and forever liberated from the destructive belief that 'Scottish Labour' answers ultimately to the party in London.

"What will the Conservative and Unionist Party even be called? Murdo Fraser's dream of an independent Scottish party will have become a reality; a party able to cast off its toxic legacy, just as the Liberal Democrats will have cast off the dark shadow of Deputy PM Clegg and his Tory deal.

"And what of the party of independence? Will Scotland still want or need an SNP?

"We will have a multitude of coalition choices, including a currently inconceivable Labour and SNP partnership."

However, the essay prompted opposition claims of "diversionary tactics" to convince people to vote for independence.

Scottish Conservative deputy leader Jackson Carlaw said: "Let's no kid ourselves that Alex Salmond and the SNP would just fade away after the referendum vote in 2014, no matter the result.

"From saying they will keep the Queen and the pound to asserting we would still be British under separation, the SNP tactic is plain to see - they will do and say anything to curry favour with as many people as possible."

He added: "Talk of whether the SNP will exist or not is just muddying the waters and another diversionary tactic in a bid to make their separation dream sound more palatable."

An SNP spokeswoman said: "The SNP will continue to work hard, now and in an independent Scotland, to earn the trust and support of voters in Scotland. We take no vote for granted now or in the future."

Patricia Ferguson, Scottish Labour's constitutional spokeswoman, said: "Given this government has ground to a halt and seems out of ideas, and that most Scots reject their core policy of independence, many people will be asking, 'what is the point of the SNP now?'.

"It is dishonest of Yes Scotland to suggest a border at Gretna will somehow free us of tough policy decisions.

"I only hope that SNP supporters like Stephen Noon are just as quick to embrace the new landscape of Scottish politics where we are free of the constitutional question if people reject separation come the referendum."