AN EXPERT on EU relations has insisted that an independent Scotland could join the union within four years - stressing the SNP's currency plan "may not be a stumbling block".

Nicola Sturgeon set out her renewed economic and borders blueprint for an independent Scotland yesterday, stressing the country would keep the pound and move to its own currency when the "time is right".

The First Minister said a timetable for creating a Scottish currency would not be set, however, use of sterling would be as "short as practicable".

Ms Sturgeon repeatedly refused to say how long that period would last, but intimated that she hoped it would be less than five years.

Until the currency is created, Scotland will continue to use sterling, but is likely to have no control over monetary policy.

In the paper, a number of economic tests must be met before such a move, including that a new Scottish central bank would establish the “credibility” of the currency, creating sufficient reserves and Scotland being “fiscally sustainable” – as well as the Scottish Parliament approving the shift.

Opponents have insisted that membership of the European Union – one of the Scottish Government’s key arguments for independence – would not be possible until Scotland has control of its monetary policy and currency, but the First Minister said negotiations for access to the bloc could go forward during the transition phase to a new currency.

But Kirsty Hughes, the former director of the Scottish Centre on European Relations, has insisted that “currency may not be stumbling block it's being taken to be” in relation of Scotland joining the EU.

Ms Hughes said that EU member states not in the Euro “must treat the exchange rate with Euro as a ‘matter of common interest’".

She added that those members not in the Euro “must aim at price stability”, but warned it was “impossible to meet these conditions if using pound sterling”.

Ms Hughes said: “But accession talks can certainly start before meeting these conditions. And there may be an alternative route.

“My views on this evolved on talking to Brussels sources who underlined a candidate using currency of a third country while in the EU is unprecedented.”

She said that “one possibility suggested was a transition period” where an independent Scotland could join the EU “while using sterling but not indefinitely”.

Ms Hughes said that whether an independent Scotland could join the EU while using the pound or whether it could negotiate a transition period “within the EU” would be “a political choice at time for EU member states”.

But she cautioned that if an independent Scotland was using the pound “without UK agreement”, then EU states could take issue, adding that “good relations with neighbours are a crucial part of accession talks”.

Ms Hughes said that an independent Scotland could “probably join the EU swiftly”, stating it could take just four or five years.

The expert said that it may take one year for an independent Scotland to obtain candidate status and initial talks, before one to two years of formal talks and then one to two years of ratification.

She added that if the Scottish pound starts after four or five years of an independent Scotland “the two processes coincide”.

Ms Hughes said: that “currency may not be stumbling block it's being taken to be”.