The former Cunninghame North MP insisted Labour had "to do more in the months ahead" to save the Union.
He said: "It's very important for people in the rest of the United Kingdom to realise what is at stake here; it isn't just the Union but it is the prospect really of there ever being a Labour government again in what is left of the United Kingdom."
Mr Wilson agreed with the estimate that for Labour to win a future general election without Scotland, it would need an additional 250,000 votes across the remaining UK.
"Scotland needs Labour and Labour needs Scotland to win because people in Scotland, the great majority of people who vote Labour, have exactly the same social and economic interests as people in Liverpool, Newcastle and Cardiff.
"The idea that we walk away from them and leave them to permanent Tory government is anathema not just to people in what would be left of the UK but to anyone in Scotland, who has an ounce of solidarity and who has (pride in) the heritage and the history what we have achieved together."
However, it has been previously pointed out that since 1945 there would have been no general election at which Scottish independence would have changed the identity of the winning party; on only two occasions would it have converted a Labour majority into a hung parliament - 1964 and October 1974.
Without Scotland, Labour would still have won in 1945, in 1966, in 1997, in 2001 and in 2005.
Mr Wilson also spoke of a "fool's gold" being offered Scots by the Nationalists; that by opting out of the UK, they would be voting in a "left-wing little Utopia in Scotland".
He explained: "What you would have is not only a right-wing government in the rest of the UK but the highest Nationalist ambition is that rightwing government in the rest of the UK would be setting our economic policy, our interest rates, our immigration policy as well as corporation tax."