A vote for independence is like buying Scotland's children a one-way ticket to uncertainty, according to the leader of the pro-union campaign.
The Better Together campaign to save the United Kingdom is being hatched in an egg-shaped lecture theatre in Scotland's capital on Monday.
Campaign leader Alistair Darling, a Scottish Labour MP and former Chancellor of the Exchequer, will make "the positive case" for keeping Scotland in the UK.
The campaign has engaged media strategists Blue State Digital, which helped bring US President Barack Obama and French President Francois Hollande to power, to build a website and oversee its online strategy.
Better Together will also distribute half a million leaflets promoting the social union between the two nations.
The leaflets highlight the one in five workers employed by English firms in Scotland, as well as those working for the UK Government in places such as the Department for International Development offices in East Kilbride.
Another points to the 800,000 Scots who live and work in England and Wales "without the need for papers or passports".
"The choice we make will be irrevocable," Darling will tell campaigners at Edinburgh Napier University's egg-shaped lecture hall in Craiglockhart.
"If we decide to leave the United Kingdom there is no way back. It is like asking us to buy a one-way ticket to send our children to a deeply uncertain destination."
Darling, echoing the message of the campaign's advertising campaign, will argue that Scotland can have the best of both worlds: "A strong Scottish Parliament and a key role in a strong and secure United Kingdom".
He will say: "The truth is Scotland's future, our future and our families' future will be economically, politically and socially stronger as a partner in the United Kingdom.
"The truth is that this coming together of family, friends, ideas, institutions and identities is a strength, not a weakness. It is an ideal worth celebrating."
Better Together will distribute half a million leaflets at train stations from Fort William to Dumfries.
A series of 10 leaflets will be produced looking at different areas where Scotland benefits from being part of the UK.
The campaign will be running full-page adverts in Scottish newspapers bearing the slogan "We want the best of both worlds": a distinctive Scottish Parliament and the strength of the UK through devolution.
Scotland's First Minister Alex Salmond formally launched his Scottish independence campaign in May. Called Yes Scotland, the movement vowed to stage the "biggest community-based campaign in Scotland's history" in the run-up to the independence referendum, which could take place as soon as October 2014.