It's suggested Trident could be moved from Scotland if the country votes for independence. We look at where the nuclear deterrent could go.
I think David Cameron feels he has made the intellectual case for staying together, now he wants to make the emotional one.
A small celebration has taken place to remember one of the biggest days in Scottish history - the Battle of Bannockburn
An independent Scotland will create a new public service broadcaster, founded on the staff and assets of BBC Scotland and funded by the current licence fee, according to the Scottish Government.
It has set out plans to set up the Scottish Broadcasting Service (SBS), offering content for television, radio and online. It states that the licence fee, which currently funds the BBC, will remain unchanged under independence.
Viewers and listeners should also continue to have access to all their current channels, its White Paper says. The new SBS will inherit a proportionate share of the BBC's commercial ventures totalling around £13 million as well as receiving licence fee revenue from Scotland to the tune of £320 million.
A formal relationship between the SBS and the BBC is proposed where SBS will continue to supply the BBC with programming in return for access to BBC services across Scotland.
Australia's prime minister has warned that an independent Scotland would not be in the best interests of the international community.
Tony Abbott, elected the Commonwealth country's 28th prime minister last year, became the latest international leader to wade into the debate after US president Barack Obama said his administration had a "deep interest" in ensuring the United Kingdom remained united.
Mr Abbott, who spent two years at the University of Oxford, told the Times: "What the Scots do is a matter for the Scots and not for a moment do I presume to tell Scottish voters which way they should vote.
"But as a friend of Britain, as an observer from afar, it's hard to see how the world would be helped by an independent Scotland.
If Scotland votes for independence next month, the remaining UK government would have to move its Trident nuclear deterrent out of the country - but a new report suggests the cost of the move would be far lower than expected.
The move would most likely take more than a decade and cost up to an extra £3.5 billion, according to a report by the Royal United Services Institute - but this is far below previous estimates of up to £25bn.
ITV News correspondent Martin Geissler has the full story.
A Ministry of Defence spokeswoman has said there are no plans to move the Trident nuclear submarine out of Scotland. It follows research suggesting that should Scotland become independent the costs of moving the weapons programme would not be as complex as previously thought.
– Ministry of Defence spokeswoman
The nuclear deterrent is the ultimate guarantor of our nation's security and no alternative would be as effective at deterring threats now or in the future. There are no plans to move Trident from Her Majesty's Naval Base Clyde and unilateral disarmament is not an option.
We are not planning for Scottish independence and as such it is difficult to estimate the total costs, or how long it would take, to replicate the facilities at Faslane, but it would likely cost taxpayers billions of pounds and take many years.
If the question mark over Trident's future could be answered, it would help untangle a difficult issue surrounding Scottish independence, Rusi research analyst Hugh Chalmers said.
"When people start considering options for relocations it's only natural to assume that it would be quite expensive and very difficult and that is certainly the case. But importantly it is not impossible.
"We estimate that essentially the net costs of relocating could actually be £2.5-3.5 billion at 2012 prices, rather than the tens of billions or even £20 billion that has been put forward so far."
But he said it would take a long time, and was unlikely to be completed by a target date of 2020, and a more "natural timeframe" would be linked to the entry of a new generation of nuclear-armed submarines, currently anticipated to start in 2028.
A research paper by the Royal United Services Institute has claimed that relocating Trident out of Scotland should the nation become independent would be both financially and technically feasible.
The paper estimates that recreating the facilities outside Scotland would add £2.5 to £3.5 billion (at 2012/13 prices) to the cost of maintaining a nuclear-armed fleet, plus the cost of acquiring and clearing the land and costs of moving people and material around, but it is very unlikely to cost "tens of billions" cited elsewhere.
But it would take more than a decade to recreate the facilities, rather than the four years to which the SNP is currently committed, the authors said.
Relocating the UK's nuclear deterrent out of an independent Scotland would be difficult but would cost far less than previously predicted, experts have suggested.
Relocating Trident in the event of Scottish independence would be feasible, although it could take more than a decade and spark significant local opposition, a new paper from the Royal United Services Institute (Rusi) military think tank has found.
But the paper suggests that recreating the nuclear facilities outside Scotland would add between £2.5-3.5 billion to the cost of maintaining a nuclear-armed fleet, plus the cost of acquiring and clearing land - but would be far less than a previously-predicted £20-25 billion.
One of the feistiest exchanges in the independence debate came as Alistair Darling pushed Alex Salmond for his "plan B" if Scotland doesn't get to keep the pound upon leaving the union.
Unhappy with his first answer in which Salmond attempted to quote his opponent, the former chancellor asked the SNP leader to "contemplate for just one minute that you might be wrong".
Mr Salmond refused to contemplate the loss of the pound as he raised his voice to be heard above shouts from the audience.
Watch the feisty exchange here: