According to the Oxford English Dictionary, a fact is "truth or reality", while an assertion is "a positive statement" or "the action of maintaining or defending a cause".

There can be a world of difference between the two. In the beginning, an independent Scotland's continuous membership of the EU was a fact, in the lexicon of the SNP. Now it appears to have morphed into an assertion. The fly in the Scottish Government's ointment is the statement earlier this week by European Commission President Jose Manuel Barroso who said it was "obvious that a newly independent country would not automatically be a member of the EU and would have to apply according to the rules". That does not appear to marry up with the impression Alex Salmond and his ministers have allowed to take root.

Once again Mr Salmond sent his deputy in to bat at Holyrood. Nicola Sturgeon's statement yesterday was the sort of polished and accomplished performance we have come to expect of her. The gist was that Scotland would remain in the EU after a Yes vote on independence, while it negotiated the revoking of the Act of Union and exit from the United Kingdom. Simultaneously, the Scottish Government would negotiate the terms of Scotland's membership of the EU and the whole process would be swift and smooth. All of this is meant to happen between the autumn of 2014 and the Holyrood elections of 2016 (during which period there may well be a change of government at Westminster). It is worth noting that Finland's uncontroversial accession took three years to negotiate, without the prospect of Spain, Belgium and perhaps others attempting to throw a spanner in the works for reasons of self-interest.

Loading article content

Ms Sturgeon maintained that nothing in the SNP's position had changed because it had always maintained that some issues would require negotiation.

However, when negotiations were mentioned before, it was in relation to relatively peripheral issues, such as the number of MEPs Scotland would elect and the country's membership of EU committees. Now such major planks of the EU as the adoption of the euro, the Schengen Agreement (on European border control) and the rebate are up for discussion.

Nobody is seriously suggesting an independent Scotland would not be welcome in the EU but a new uncertainty hangs over the terms and timetable. Although Ms Sturgeon is correct to maintain that Mr Barroso is not the final arbiter, nor is she. While Scottish ministers can always find academics to back their version of the future, others disagree.

Ms Sturgeon is probably right to say an independent Scotland would not be obliged to adopt the euro or Schengen immediately, but the rebate could become a hot potato. Politicians of any stripe often like to think that, if they repeat an assertion often enough, it will become fact. That is not necessarily the case.