The prime minister has insisted he remains committed to keeping defence jobs in Scotland as he prepares to welcome home a submarine crew from their 100th patrol.
David Cameron will visit crew from HMS Victorious, one of the Royal Navy's Vanguard-class submarines, in the west of Scotland, and host a PM Direct event at a local defence contractor.
David Cameron will say that defence is stronger and safer together with Scotland part of the UK
Cameron will tell workers that the defence sector employs 12,600 people in Scotland, amounting to around 0.5% of the working population.
Jobs include shipbuilding, manufacturing, and making components for jets which are sold to foreign countries.
"Defence matters, and defence jobs matter," Cameron said before his visit.
"Scotland has a world renowned and highly skilled defence sector that employs over 12,600 people and has annual sales in excess of £1.8 billion.
"It plays a key role in equipping and supporting the UK Armed Forces, from iconic industries like shipbuilding on the Clyde and Rosyth to cutting-edge, high-tech manufacturing.
"Being part of the UK opens doors for the Scottish defence industry around the globe. When we sell Typhoons overseas, this benefits jobs and growth for companies making components in Scotland.
"Scotland counts for more on the world stage because it is part of the United Kingdom and Scottish defence jobs are more secure as part of the United Kingdom.
"The business community tell me that they want certainty. And I want to offer that certainty by saying that I remain absolutely committed to the defence of the United Kingdom and to the future of defence jobs in Scotland.
"Defence matters. We are stronger and safer together."
The SNP say that Cameron should use his visit to Scotland to apologise to Scottish communities for "constant broken promises on defence".
Angus Robertson, defence spokesman for the SNP, said: "We have already heard the prime minister admit that commitments made to communities around Scotland have been broken, but there has been no apology.
"It is just the same old, same old from Westminster which reduced Scotland's service personnel jobs by 27.9% between 2000 and 2010, when the it was only 11.6% across the UK.
"Successive Westminster governments oversaw the destruction of the Scottish regiments, and contributed to a massive £7.4 billion defence underspend in Scotland compared to the rest of the UK.
"It just shows that when it comes to defence Westminster isn't working for Scotland, and an independent Scottish Parliament would take far better defence decisions for Scotland."
HMS Victotrious returns from its 100th patrol on Thursday
Meanwhile, a Commons committee claims that Clyde shipyards do not have a future in an independent Scotland following the UK Government response to a report on the effects of separation.
The Scottish Affairs Committee has published the UK government's response to its report, The Referendum on Separation for Scotland: Separation Shuts Shipyards. It states that building complex warships within the UK is "critical to our national security".
At present contracts for UK warships must be placed in the UK and consequently "Scottish shipyards would not be eligible to bid for contracts to build complex warships for the Royal Navy if Scotland was to become independent," according to the UK government.
Ian Davidson MP, chair of the SAC, said: "In these circumstances it is difficult, if not impossible, to see how the Clyde yards can have any long term future in a separate Scotland.
"This problem, of the future of the shipyards on the Clyde, is not however a problem that can be delayed until after separation or indeed until after the referendum. The Clyde yards will soon complete their allocated share of the aircraft carrier order and will therefore run out of work.
The SNP have asserted that shipbuilding in an independent Scotland would continue to thrive.
Robertson said: "We know from evidence from Vice-Admiral Mathews to Westminster's Scottish Affairs Committee, reinforced by defence expert Ian Godden, chairman of Farnborough International, that an independent Scotland can get defence contracts from the rest of the UK and around the world on the basis of our expertise and industrial and engineering capabilities."
Labour MP Margaret Curran, the shadow Scottish secretary, said: "On Monday, David Cameron's government introduced the bedroom tax, and on Saturday he's giving millionaires a tax cut worth double the average Scottish wage.
"Perhaps while he's here he can look Scots in the eye and justify these changes. Or he could follow in Iain Duncan Smith's footsteps and go to Easterhouse to explain the impact of his bedroom tax.
"Scots know we don't need more of the same. We need a change of course and a government in Scotland and across the UK who will work in the interests of all, not just the few at the top."