David Cameron will continue his visit to Scotland today to make "the positive arguments in favour of Scotland remaining part of the UK."
The Prime Minister is expected to speak to youngsters in the south of Scotland to discuss the referendum on the final day of his two-day trip.
He said only a No vote in the independence referendum would ensure the future of devolution.
Speaking on a visit to Walcheren Barracks in the Maryhill area of Glasgow yesterday, he said: "It's very important if you want further devolution, the way to get it is a No vote. A Yes vote is an end to devolution, it's the start of irreversible separation.
"As Prime Minister over the last four years, I made promises about further devolution for Scotland, I think some people might have doubted whether they were going to be fulfilled, but they have absolutely been fulfilled, the Scotland Act is one of the largest acts of devolution that has ever taken place.
"Scotland knows that it has a good level of devolution already and would have the opportunity for more devolution in the event of a No vote."
First Minister Alex Salmond said people will not believe promises of further devolution and reiterated calls for a debate with the Prime Minister on independence.
He said: "The Prime Minister is perfectly entitled to come to Scotland, and we are perfectly entitled to ask why he isn't prepared to have a debate in Scotland. He is prepared to have a debate with Ukip and the Greens, but not on the future of Scotland.
"If you are entering a debate, you cannot be half in that debate - you have to be accountable, which is why he should agree to a one-to-one TV debate, First Minister to Prime Minister."
Mr Cameron will also campaign in the North East and North West of England.
