Image copyright Science Photo Library Image caption How will Osborne's announcement affect Scottish voters' psychology?

The UK government's announcement that it will seek to block a formal currency union in the event of Scottish independence is a significant intervention in the referendum debate.

The move has attracted strong criticism from the Scottish government, which has described it as "bullying and intimidation".

But how will the Scottish public react to the announcement? Will the economic uncertainty generated by the announcement benefit the 'No' campaign, or will Scots feel unfairly treated and be more likely to vote 'Yes'?

The BBC spoke to leading social psychologists, who believe the announcement will polarise Scotland's referendum debate.

What have the Scottish public said?

On Friday morning, on BBC Radio Scotland's phone-in Morning Call programme, the opinions of Scottish voters appeared to be mixed.

Stuart from Glasgow said the three main Westminster parties were "ganging up" on Scotland. He added: "I've been pretty apathetic all my life, but when I saw the three parties ganging up like that it got me from apathy to anger. I got on the computer last night and registered to vote. I'm going to vote for independence now."

Kaye from East Lothian said Scots do not "bend to bullying", and added: "It is absolutely bullying, by all three parties. I'm angry about it, and [the Westminster parties] should do well to remember that, even people who maybe would have voted no, will now be thinking 'hang on, we are not being treated equally'."

Image copyright PA Image caption Currency has taken centre-stage in the debate

However, Alastair, a Scottish businessman, said clarity was more important. He added: "Finally we've got clarity in what the currency will be which is good, we know that we will not have the pound, but what we now need to know is what the alternative would be in an independent Scotland. The bluster is just political posturing from either side."

What do the experts say?

Dr Tereza Capelos, from the University of Surrey, is a specialist in political psychology, electoral behaviour and public opinion.

She said: "Bullying is a strong word but it might not be far from reality in terms of how this might play out in the hearts of particular audiences.

"If a particular element of an issue is highlighted, that will become the dominant consideration in the public's perception of the issue. This is known in political psychology as priming."

Dr Capelos predicted that pro-independence Scots would react in three ways to the 'political priming' of currency concerns:

Those with a more risk-averse approach, who also consider the issue of currency important, might feel intimidated and back away from supporting independence

Those who are more risk-seeking might dismiss it as a rhetoric exercise, and may solidify their position towards independence

Those who consider the currency issue important, but feel they have been treated unfairly, will be even more inclined to vote Yes.

Which one of these routes voters take will be affected by the response of other politicians, in a stage known to the experts as "spinning".

'Mobilise outrage'

Image copyright Getty Images Image caption Will the UK or the Scottish government benefit from the announcement?

Dr Stephen Reicher, a social psychologist from the University of St Andrews, thinks popular perceptions of Scotland's history will help the Scottish government "spin" Osborne's announcement in their favour.

He said: "In the Scottish case, there is a strong strand, going from tales of the clearances to the early imposition of the Poll Tax, which can be used by the Scottish government to argue that the Westminster establishment use and abuse Scotland for their own ends.

We either have a triumphalist vote for independence or else a sullen and resentful vote against. Neither bodes well for harmony in the UK Dr Stephen Reicher

"There is also a strong strand, dramatised in films like Braveheart and Rob Roy, to say that 'true Scots' challenge abusive authority.

"This makes it all the easier for politicians to mobilise outrage against the decision."

Dr Reicher added that voters may transform from apathy to anger due to a psychological process called reactance.

He said: "If people see (or can be persuaded to see) their autonomy being removed, they will respond by asserting their autonomy even if that means doing something which they are not particularly favourable to for its own sake.

"When one is told 'oh no you can't' (be part of a currency union), the response 'oh yes we can' becomes more likely."

'Radicalise'

However, the most likely outcome of the UK government's announcement is that it will harden opinion on both sides of the debate.

Dr Reicher said: "Osborne's announcement will strengthen the sense that England dominates Scotland and imposes its will and interests on Scotland, but increase the sense that independence risks Scotland's economic interests.

"I think the real danger of this intervention is that it polarises and radicalises the debate. Either Scots support independence in the expectation that they can overcome the UK government, or they vote against because they feel they can't challenge the power of the UK government.

"We either have a triumphalist vote for independence or else a sullen and resentful vote against. Neither bodes well for harmony in the UK."