Plans for a major drive to give English MPs a key role emerged after two north-east MPs yesterday held talks in Edinburgh with Scotland Office officials and Scots Labour leader Johann Lamont.
Details of the initiative came as a YouGov poll suggested that strident No campaign claims about the damaging economic consequences of independence had backfired as support for a Yes vote continued to grow.
In a further sign the pro-UK side is changing the tenor of its campaign, Scottish Secretary Alistair Carmichael will tell an audience at Edinburgh University tonight that supporters should be "less shy about talking up the benefits the UK brings us".
The growing role of north of England MPs emerged after Labour's Phil Wilson, Tony Blair's successor as MP for Sedgefield in County Durham, and Bridget Phillipson, MP for Houghton and Sunderland South, travelled north to argue that independence would damage their region economically and was at odds with strong cross-Border family ties and shared history.
They also want to challenge the SNP's portrayal of England as an alien political land with an overwhelmingly right-leaning outlook.
Ms Phillipson, who is the grand-daughter of a Scot, said: "We think there are such close connections between the north-east and Scotland.
"There are ties of history, shared industry and for many of us family ties as well, and that's important.
"We are looking at how we can work together more closely and improve trade rather than making that more difficult by putting up artificial barriers and separating."
Coal miner's son Mr Wilson said: "What we need on either side of the Border is further co-operation, not competition.
"We've been part of a Union for 300 years, why would we want to lose it?"
Highlighting the shared industrial heritage of coal mining, shipbuilding and steel-making between Scotland and the north-east of England he added: "Not everyone south of the Border sounds like David Cameron - as you can tell from our accents.
"To try to portray all English people like that is disrespectful to a lot of English people."
Ms Phillipson said people in the north-east of England had more in common with Scots than people in the south of England.
She added: "People in the north-east, for large parts of the 1980s and 1990s, felt very cut off from what was going on in London.
"We felt that acutely and that's why it's vital the Labour party wins elections and puts us in a position to deliver on jobs and investment for our region and Scotland."
Growing economic links between Scotland and the north-east of England are being built around the petro-chemicals industry and Hitachi's new County Durham rail train plant.
The two MPs fear trade would be put at risk if Scotland voted to leave the UK.
Labour insiders said similar pleas to stay in the UK - dubbed "lovebombing" - would be made by MPs from Manchester, Liverpool, Leeds and other north of England cities in the coming weeks.
The effort to challenge the SNP's portrayal of England as a right-leaning country came as the same YouGov poll yesterday showed just 19% of voters across the UK saw Labour leader Ed Miliband as a prime minister-in-waiting.
The finding came as a blow to Labour despite the party retaining its narrow lead over the Conservatives ahead of next year's general election.