The British government on Sunday pledged greater fiscal autonomy for Scotland, after a poll put the pro-independence camp ahead for the first time -- just 11 days before the referendum on separation.
British finance minister George Osborne said greater tax and spending powers would be announced in the coming days and would be implemented if Scotland votes on September 18 to retain the 300-year-old union with England.
The offer came after a YouGov poll in The Sunday Times newspaper gave the pro-independence "Yes" camp 51 percent support compared to the "No" camp's 49 percent, excluding undecided voters. Six percent said they had not made up their minds.
Although the two-point lead is within the margin of error, the findings dramatically up the stakes ahead of the vote.
Scottish First Minister Alex Salmond, of the separatist Scottish National Party (SNP), dismissed Osborne's move as a "panic measure", saying it was "ridiculous" to announce it now, with many people having already voted by post.
Reacting to the poll, Osborne told BBC television: "If people were in any doubt that they can stay at home, that they don't need to go out to the polls and vote 'No' to avoid separation, they won't be in that doubt today.
"They should also be in no doubt about the consequences of this decision," the chancellor of the exchequer added.
"No ifs, no buts: we will not share the pound if Scotland separates from the rest of the UK."
- 'Best of both worlds' -
Osborne said it was "clear" that Scots wanted greater autonomy and the three main United Kingdom-wide parties -- the Conservatives, their Liberal Democrat junior partners in government and the Labour opposition -- had agreed to "deliver" on that.
"You will see in the next few days a plan of action to give more powers to Scotland. More tax powers, more spending powers, more plans for powers over the welfare state," he said.
"Then Scotland will have the best of both worlds.
"They will both avoid the risks of separation but have more control over their own destiny, which is where I think many Scots want to be."
Any vote for Scotland to leave the UK would raise questions about Britain's standing in the international community.
Scotland represents one-third of Britain's landmass and is home to Britain's submarine-based Trident nuclear deterrent, which the SNP says must be out of an independent Scotland by 2020.
Salmond claimed the momentum was now "decisively with the 'Yes' campaign".
"The Westminster elite are losing this campaign... we've got them on the run," he told BBC television.
He said there was "clear panic in the 'No' campaign. They've failed to scare the Scots; now they're trying to bribe us".
The Better Together campaign, which backs Scotland staying in the United Kingdom, has been ahead in opinion polls for months but its lead has narrowed in recent weeks.
The "No" camp had a 22-point lead in YouGov polling just one month ago. Another YouGov survey for The Times newspaper on Tuesday showed a marked narrowing of the gap to six points.
- 'Irreversible decision' -
Osborne's Labour predecessor Alistair Darling, the Better Together leader, said the latest poll showed the referendum "will go right to the wire".
"Every voter in Scotland can now tip the balance in this referendum," he said.
"It's not a protest vote, it is about the future of our country. If we decide to leave, there is no going back."
A second survey commissioned by the "Yes" camp and released on Sunday puts the "No" camp four points ahead. The Panelbase poll gives "No" 52 percent and "Yes" 48 percent, excluding undecideds.
Gordon Brown, Cameron's Labour predecessor as prime minister, blamed Conservative policies for hindering support for the union.
But the Scot said whatever government was "temporarily" in power -- a UK-wide general election is due in May -- that should not be a basis for an "irreversible decision".
"The underlying mood of the electorate voting in this referendum is they want change," he told Sky News television, but stressed the best way to get it was through greater autonomy rather than breaking "every single link" with the rest of the UK.