04/07/2014 05:47 BST | Updated 02/09/2014 06:59 BST

Scotland's Shipbuilding Future Lies in Defending the UK

Today is a proud day for Scotland and the United Kingdom. It is also a proud occasion for the workforce on the Clyde. Because the history of shipbuilding runs deep in Scotland.

The yards along the Clyde, and the dockyard at Rosyth, weren't just workplaces, they dominated and shaped communities. There is hardly a family today in and around Glasgow which doesn't have a connection to the shipbuilding industry. Those who worked in the shipyards didn't just learn a trade, they learned how to organise, grew in their politics, made friends for life and passed it all on to the next generation. And, along with their colleagues in yards around the United Kingdom, they were the best in the world at what they did.

Today's naming of the HMS Queen Elizabeth shows that those traditions are alive and well. It tells people that shipbuilding in Scotland isn't just found in the pages of history books, it is a very tangible and important part of Scotland's industrial landscape.

HMS Queen Elizabeth is the biggest warship ever to be built in the UK, and it has steadily grown in the dry-dock at Rosyth in Fife over the past few years. While the ship has been assembled in Scotland, the project is the result of work at six UK shipyards from Portsmouth to Glasgow. Nine huge sections of the carrier have been built around the UK.

The blocks built in the Clyde shipyards at Govan and Scotstoun have provided jobs for thousands of men and women and has retained shipbuilding skills on the Clyde. This isn't just important for Glasgow, it's important for thousands of people across the Scotland who find employment at these yards.

Supported by the trade unions, there is also a growing apprenticeship programme. This means not only a trained workforce for the industry in the future, but also the retention and renewal of shipbuilding skills that were dismissed and diminished through the neglect of the Thatcher years.

We take great pride in the shipbuilding industry in Scotland and the United Kingdom and we both want to see it go from strength to strength. The industry has recognised the skills and expertise that exist on the Clyde, and that is why BAE systems are investing over £200 million in the yard at Scotstoun over the coming years.

On the numerous occasions over recent months, we've met with the shop stewards from Rosyth and the Clyde, who tell us that the biggest threat to Scottish shipbuilding comes from the SNP's plans for separation.

As Duncan McPhee, Unite the Union's Convenor at Scotstoun said "if Scotland decides to become independent from the UK the shipyards at Scotstoun and Govan will lose their only customer."

Like the shop stewards, we know that separation risks the future of shipbuilding in Scotland. With no immediate prospect for export orders, and no indication from the Scottish Government that there would be any new ships built for a 'Scottish Navy', the yards would face a deeply uncertain future with independence.

The SNP are causing uncertainty and concern for the 15,000 people whose jobs depend on Scotland's role in the UK's defence industry. We are clear that the only way to end that uncertainty is by ensuring Scotland's shipbuilding industry is in a Scotland inside the UK.

Today, everyone across Scotland can take pride in the ships we build and the contribution they make to keeping our country safe and secure.

HMS Queen Elizabeth, which we will launch today, will have a long life. The final Captain to serve on that ship hasn't even been born yet. We want Scotland's shipbuilding industry to have as long a future. The way to achieve that is to say No Thanks to separation in September.