Speaking at the opening of of the Scottish Conservative party's spring conference in Edinburgh, the prime minister is expected to say the referendum is "a major life decision" that shouldn't be made without knowing the full consequences.
He is expected to add:
And look at who's laying out those consequences: the governor of the Bank of England, the president of the European Commission, business chiefs from companies like BP and Shell; Alliance Trust and RBS; Lloyds, Barclays - the list goes on.
These are not political puppets, they are serious, non-partisan figures.
So, the idea that these are empty warnings and political scare-mongering is a myth - and we owe it to the people of Scotland to take that myth apart.
David Cameron will focus on his fight to keep Scotland in the UK as he opens the Scottish Conservative party conference later today.
He is due in Edinburgh, where he will draw on recent interventions from major businesses, such as BP and Shell, in the referendum debate.
Mr Cameron will attempt to tackle accusations of "scaremongering" over the country's future, saying he wants to "take that myth apart".
Our Political Editor looks to the North East of Scotland where the Prime Minster and First Minister have been discussing the future of oil.Read the full story ›
The Scottish Nationalists attacked the Prime Minister for politicising the Olympic spirit and again challenged him to debate independence with First Minister Alex Salmond.
Speaking after David Cameron's speech at the Olympic park in London, Deputy First Minister Nicola Sturgeon said the Prime Minister “hasn’t got the guts” to come to Scotland to deliver the speech.
David Cameron today invoked the Olympic spirit of Team GB to make the case against Scottish independence.
The Prime Minister says the UK would be deeply diminshed without Scotland.
Mr Cameron called on people in England, Wales and Northern Ireland in favour of the union to make their voice heard even though they don't have a vote.
Here's some of the Prime Minister's speech.
The Prime Minister has given an Olympic themed speech urging Scotland to remain in the UK.
Speaking at the Olympic Park in London, David Cameron said the whole of the UK will lose out if Scotland votes for independence in the referendum.
ITV Border's Political Editor dissects the Prime Minister's independence speech.Read the full story ›
The Prime Minister will deliver an Olympic themed speech as he urges Scotland to remain part of the UK later today.
At the Olympic Park in London, David Cameron will argue that the whole of the UK will lose if Scotland votes for independence in the referendum.
David Cameron is "cowardly" for encouraging unity from London and not debating Scottish independence in Edinburgh, the deputy first minister of Scotland has said.
Nicola Sturgeon said the speech was a sign of the "jitters" running through the No vote camp.
This is a cowardly speech from a prime minister who uses the Olympic Park in London to give high-handed lectures against Scotland's independence but hasn't got the guts to come to Scotland or anywhere else to make his case in a head-to-head debate.
David Cameron, as the Tory Prime Minister, is the very embodiment of the democratic case for a Yes vote for an independent Scotland - and he knows it....
A Yes vote will put Scotland's future in Scotland's hands, and will mean we will never again have to endure Tory governments, prime ministers and policies we didn't vote for.
Everyone living in the United Kingdom will be "profoundly affected" by outcome of the Scottish independence referendum, David Cameron is expected to say in a speech later today.
Speaking from the Olympic stadium, the Prime Minister will argue that the UK is a "powerful brand" in the modern world, with a global reputation for being "unique, brilliant, creative, eccentric, ingenious".
My argument today is that though only four million people can vote in this referendum, all 63 million of us are profoundly affected.
There are 63 million of us who could wake up on September 19 in a different country, with a different future ahead of it.
That's why this speech is addressed not to the people of Scotland, but to the people of England, Wales and Northern Ireland...
We would be deeply diminished without Scotland. This matters to all our futures. And everyone in the UK can have a voice in this debate