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.
More top news
Shadow Cabinet set to meet for "most important gathering" they've had since Corbyn appointed members to their positions.
A pensioner described as a mastermind of the Hatton Garden heist used a Freedom Pass to get there, a court has heard.
Excitement builds among Doctor Who fans after director Peter Jackson sparks speculation he could direct an episode of the hit show.