Last year, I served on the Parliamentary Commission on Banking Standards, investigating the failures that led to the financial crisis.

I know from the evidence I heard that the failures in our banks were caused by those at the top not taking their responsibilities seriously and convincing people that everything would work out in the end. Looking at some senior Nationalists in Scotland today, the behaviour looks very similar. They are willing to take a gamble with our future to serve their short-term interests.

The commission spent 18 months trying to get to the bottom of the issues and making sure that we had the answers from the people we had before us. It didn't matter whether that was a chief executive, a government minister or a civil servant. I won't shy away from asking tough questions of the SNP's plans for separation. I know that people across Scotland deserve to get the answers before we vote on September 18. We need to go into this referendum with our eyes wide open.

Loading article content

This evening, I'll be in the east end of Glasgow with Shadow Scottish Secretary Margaret Curran speaking at a roundtable event with small businesses based in the area. These are some of the businesses that keep Glasgow going. They might have relatively small turnovers but they keep people in work across the city, often in areas with few major employers.

My message to them will be clear. The SNP's plans are bad for business and bad for jobs. As part of the House of Lords Economic Affairs Committee, I spent almost a year looking at the economic implications of Scotland separating from the rest of the UK, and these were the conclusions I reached:

First, the Union we have developed over the past 300 years has become closely integrated. The UK market is even more of a single market than the EU or any other "free trade" zone around the world.

For the business leaders I am speaking to, this means unfettered access to consumers in England, Wales and Northern Ireland, which means a potential unrestricted market of 65 million people, instead of just five million.

It also means that a small business that might have to deal with complex trade rules inside the EU doesn't have to worry about similar problems when they are exporting from Edinburgh to Exeter.

Secondly, for small Scottish companies working across the UK, independence would mean that they would have to deal with not one but two regulatory environments.

While large companies working in numerous territories across the world may do this with ease, small businesses are more likely to find this an expensive barrier to working across borders.

Some 70% of Scottish trade is with other parts of the UK, so it's no surprise that Scottish businesses have told me they are worried about what this could mean for the ease of working across the Border in the future.

Finally, and most fundamentally, the SNP can offer no answers on what currency a separate Scotland would use. Gone are the days when Alex Salmond said the pound was a "millstone around our necks". Now he embraces it wholeheartedly. But the three major political parties have ruled out a currency union because it is not in the interests of either Scotland or the rest of the UK.

This is because they have learned the lessons of the Eurozone (where monetary and fiscal policy is split)and can see the major problems this can cause.

And for Scottish businesses it could mean higher borrowing rates and more uncertainty about the future.

The future of our country will be determined by the outcome of the referendum. It will also determine the future prosperity of Scotland's economy. We've made the mistake of believing assurances from the men at the top before.

The stakes for Scots are even higher this year than they were during the financial crisis. Let's not make the same mistake again.