The plea for an honest and decent debate is made by the independence-supporting couple Colin and Chris Weir, who won the £161 million EuroMillions jackpot.
In a letter to The Scotsman, the Weirs also defend their right to donate £3m to the Yes movement and describe their dismay at the abuse to which they have been subjected as a result of their political beliefs.
The Weirs have taken the rare step of making a public statement about the referendum in the hope of raising the level of debate to ensure that the country does not become permanently fractured.
In their letter, the Ayrshire couple, who became the UK’s largest lottery winners when they won the EuroMillions jackpot in 2011, say all Scots will have to live together after the referendum, regardless of the outcome.
Mr and Mrs Weir add: “That will only be possible if both sides of the campaign, the politicians and the media, take responsibility for their behaviour and language in the next few months.
“They are the ones who will steer Scotland through this challenging period – we can’t have the possibility of leaving our country fragmented.
“So it is time for all sides to stop the smears and personal attacks before a line is crossed and attitudes adopted that cannot easily be healed.
“No-one – on any side – should be vilified for the views they hold, lest our democracy become the victim of the present debate.
“Differences can and should be expressed – but decently, with honesty and integrity… Otherwise, in a race to the bottom of the political barrel, we will all be the losers.”
In their letter, the couple say after their win, they took a decision not to speak publicly about any aspect of their lives, arguing that they are not celebrities, politicians or public figures.
But the tone of a recent article in the press and a series of unpleasant slurs made against them online has encouraged them to speak out.
“Our silence… has meant that, from time to time, we have been subjected to comment and speculation, the majority of it kind and generous, some of it mischievous or ill-informed and, occasionally, some of it downright nasty,” the letter says.
“But, in the words of one friend, we have ‘sucked it up’ because those whose opinions matter to us know the truth. And we trust the public to recognise the difference between fact, speculation and idle gossip.
“But even we have to say ‘enough’, when we are denigrated in the most personal of ways.”
The letter is published as concern mounts on both sides of the political divide about unpleasantness generated by the debate. A new Vote No Borders organisation, which is campaigning against independence, yesterday expressed concern about the “virulent” and “nasty” online attacks “whipped up” by Nationalist websites.
A statement issued by Vote No Borders, which has been founded by the Greenock-born financier Malcolm Offord, condemned the “dangerous witch-hunting” by some internet sites.
It also criticised the “wholly unreasonable level of venom” directed at young musicians who appeared in support of the campaign on television.
Meanwhile, in their letter, the Weirs take issue with the suggestion that they were “targeted” by senior SNP figures once their lottery win became public.
A recent tabloid article referred to the fact that First Minister Alex Salmond wrote to Mr Weir after the win to offer his congratulations. Mr Salmond’s letter made reference to the fact that he and Mr Weir, a former TV cameraman, used to work together on SNP political broadcasts.
The couple, who have long supported the idea of Scottish independence, were then invited to Bute House, the First Minister’s official residence in Edinburgh.
In their letter, Mr and Mrs Weir write: “As lifelong supporters of independence, it would be strange if we did not support the Yes Scotland campaign. So that is what we have done, nothing more and nothing less.
“No-one bullied or targeted us, as has been suggested in recent newspaper articles. The only ‘targeting’ has been by an MSP who chose to express his ‘concern’ for us by implying we have been, at best, naive, and, at worst, duped.
“Would he, we wonder, have felt the same concern had our contribution supported his cause?
“The people of Scotland are not gullible. They aren’t going to vote based on how much money we have given to a particular campaign – they will make their decision based on being well-informed.
“That’s why we made the donations we did, to ensure there was the chance of an informed debate. Beyond that, it’s up to the voting public to decide, not us – we only have two votes.”
Last night, a spokesman for Yes Scotland said: “Colin and Chris Weir, who are known for giving generously to a range of good causes, happen to be committed supporters of Scottish independence and have been for many years, long before they became lottery winners.
“They have said that those who share their view should try to support the campaign with whatever they could afford and that is what they have done. They deserve to be treated with courtesy and respect.”
A spokesman for Better Together said: “Nobody should be attacked because of how they plan to vote in September.
“Everybody should feel free to express their view without fear of abuse.”