The papers: 'An act of pure evil'
The late breaking news of the murder of British hostage David Haines arrived too late for the national papers' first editions, but some online editions carry the story.
The Mail on Sunday shows harrowing pictures taken by the Islamic State extremists before the murder.
It says aid worker Mr Haines, a father-of-two who grew up in Perth, was forced to denounce David Cameron before being killed.
A video of the killing was posted online before being removed 'as a violation of YouTube's policy on shocking and disgusting content".
Mr Cameron's statement said the beheading was "a despicable and appalling murder of an innocent aid worker. It is an act of pure evil."
The Sunday Telegraph says the murder came just hours after his family urged his captors to contact them.
The paper says Mr Haines, who had been held captive since March last year, was believed to have been seized by a gang which later sold him to IS fanatics.
The paper says the PM will chair a meeting of the emergency Cobra committee. This is due to start at 10:00 BST on Sunday and will also be attended by the Home Secretary Theresa May, Foreign Secretary Philip Hammond and Defence Secretary Michael Fallon.
It adds: "Mr Cameron rushed back to Downing Street for crisis talks with his advisers, officials and intelligence chiefs on Saturday night. He arrived at No 10 just after midnight."
The Observer says the voice of the man who appeared to behead Mr Haines sounds like that of the voice of the man who was pictured in videos with and is believed to have killed American hostages James Foley and Steven Sotloff.
The paper notes, "the video, which runs to two minutes and 28 seconds, ends with a warning that a second British hostage would be the next to die".
The Sunday Mirror quotes Col Richard Kemp, former commander of British forces in Afghanistan, as saying "having worked in British Government on hostage rescue I know how much effort has gone in to saving David Haines. Now is the time for retribution."
'Sinner of history'
In the print editions, Scotland's referendum still dominates with a host of polls and a cavalcade of opinion pieces, from politicians and celebrities.
The Sunday Times headlines on David Cameron's message to Scottish voters that there will be "no way back" if they vote for independence.
It carries a poll by survey firm Panelbase which finds the No to independence vote holding a "wafer thin" lead over Yes by 50.6% to 49.4%.
Within the paper, veteran pollster Peter Kellner says a No vote is the "more likely outcome".
Kellner doesn't discount the possibility of a Yes victory, but he says the lessons of other similar referendums - including Quebec in 1995 and the Scottish devolution referendum in 1979 - was "voters approach polling day, look over the cliff edge and some of them decide, after all, not to jump".
In the Observer, a poll by Opinium puts the No campaign at 53% to 47% for Yes.
The paper notes that less than 3% of those asked say they might change their mind, meaning that Alistair Darling's prediction, headlined in the paper, that No will win, might be right.
The Independent on Sunday carries the result of internal canvassing by the Labour Party which suggests party strongholds such as Glasgow and Dundee who were "broadly backing independence in mid-August" are now staunchly against independence.
Bucking the trend of the polls in other papers, an ICM survey for the Sunday Telegraph gave the Yes camp an eight-point lead.
But noting the contradictory nature of such research, the paper notes a Survation poll commissioned by Better Together, put the No's in the lead by the same margin.
The Mail on Sunday carries a whole Britain poll which suggests that a post general election UK would have a Labour majority of 44, but without Scotland the party would only be nine seats ahead.
In the Sun, an all-Britain poll shows a Scottish majority for independence, but only 30% of the whole UK backing it.
It also found that 50% of those outside Scotland say the country should not be readmitted to the UK if independence turns out to be a bad idea, 43% say the UK military should not protect an independent Scotland, and 49% say Scots should not be allowed free access to the rest of the country, in the event of a Yes vote.
The Observer looks at how the referendum is being covered overseas, noting that in Spain, Catalan nationalists are hailing the vote as an example they want to be followed by the Madrid government, and lauded Mr Cameron as a leader "who respects democracy".
The paper adds that in China, an official neutrality is not followed by observers who - mindful of China's own separatist movements - say the British PM will go down as a "sinner of history" if the UK breaks up.
In Russia, antipathy towards British foreign policy has led many nationalists to back the Yes vote and compare the Scots to eastern Ukrainian separatists.
The great, the good - and the perhaps less distinguished - all wade into the independence debate in Sunday's press.
In an interview, the Sunday Times says Alex Salmond exudes "no bravado, far less any triumphalism, but... a quiet confidence."
Eschewing "outdated" nationalistic slogans about "freedom", Mr Salmond tells the paper: "We don't need to rise and be a nation again - we just need to register to vote, and then believe in ourselves."
Facing Mr Salmond on the page, Better Together leader Alistair Darling is scathing about the Yes campaign hecklers who have dogged his speaking engagement, leading to often violent confrontations.
Of his rival Scot, Mr Darling says: "Basically Salmond is saying 'trust me, I'm right, and the rest of the world is wrong'. That's a huge gamble to take with your family and the country."
He adds that in his opinion, independence could not possibly be agreed and signed off by 2016 but would involve "years and years of wrangling".
John Cridland, the director general of the CBI, writes in the Mail on Sunday that "business hates uncertainty, and the future of an independent Scotland is unclear. It's not a question of whether it survives, but of how well it prospers".
Labour's John Reid, a former secretary of state for Scotland, writes in the Sunday Express that the nationalists "have run their campaign like a parody of Monty Python's 'What did the Romans ever do for us' sketch?
He lists financial stability, economic growth, and the NHS among the things, the nationalists would have to concede the Union provides.
Former education secretary Michael Gove adds his opinion in the Sun.
Aberdeen-born Mr Gove writes of his pride at being Scottish, adding: "I believe in the United Kingdom because it is a Scottish creation which embodies a key Scottish value — we all achieve more as individuals when we unite with a common purpose."
The paper juxtaposes Mr Gove's views with SNP MP Angus McNeil who says the No campaign is "anti-Scottish" and relies on "scare tactics".
Among the pundits offering their views from a less political perspective is Deacon Blue singer Ricky Ross in the Sunday Express.
He says the desire for independence is not caused by "English hating", or a "desire to settle old scores".
"There is simply a growing awareness that we are perfectly able to govern ourselves," the pro-Yes pop star adds.
Singer Susan Boyle in the Sunday Mirror takes a different view.
"Economically, the costs of change will be vast. Money that should be spent on hospitals, schools and vulnerable people will be swallowed up by bureaucracy," she writes.
In the Sunday Times, Jeremy Clarkson takes a semi-humorous look at the question and decides "if Scotland goes, there will be years and years of fighting about who owns what.
"We're not talking about a record collection, and who gets the cat. We're talking about the fabric of a nation: money, art, the health service, nuclear weapons. This would be the most acrimonious divorce in history."
With Alex Salmond popping up in nearly all papers, his near namesake, the salmon, features in two.
The Independent on Sunday writes about the poaching of wild salmon and other large fish, including carp.
The paper says criminal gangs have moved in on what is a "horrendous crime" which has been "under the radar" of the authorities.
The National Wildlife Crime Unit is quoted in the paper as saying: "Offenders can net up to 100 salmon at a time, with a large fish worth around £100 on the black market.
"Much of the illegally rod-caught wild salmon in Scotland is believed to end up in top restaurants in London or on the continent."
Another problem the paper adds is illegal fishing for food by migrant Eastern European workers, who are often unaware of the UK's fishing restrictions.
The situation is such that in Lincolnshire, Polish police officers are being brought to the country to help tackle the problem.
Should all this make you fancy tucking into some fresh fish, heed the article in the Sunday Times about salmon.
It says that smoked salmon made from fish farmed in Scotland has twice the fat content of a margherita pizza.
The paper notes that the fish is often marketed as "lean" and "healthy".
Smoked salmon from wild stocks has much less fat, it adds.
It quotes Don Staniford of Global Alliance Against Industrial Aquaculture, who says, "the farmed salmon is a couch potato compared to the majestic and iconic wild salmon".
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