INDEPENDENCE and the creation of "an unnecessary international border" would hamper transport links between Scotland and England, Patrick McLoughlin, the UK Transport Secretary, has argued.
Speaking to business leaders in Scotland last night, the Secretary of State argued that a No vote in September's referendum would ensure Scotland continued to benefit from joint transport links.
He said: "If Scotland is to flourish in the future, it needs to be an outward facing nation; a country that welcomes people and investment from abroad, that builds strong connections with international partners and that's wired into the global economy.
"Where we differ from the pro-independence lobby is we believe Scotland has a better chance of achieving those goals if it's part of the United Kingdom, part of a bigger, more powerful block, in which people and goods can all move freely, unconstrained by international borders where devolved administrations work alongside the Westminster government on a shared vision to improve transport throughout the UK."
The Transport Secretary set out how Scotland was benefiting from major investment in rail, which is shortening journey times and boosting the Scottish economy by around £3 billion.
He also emphasised how the Coalition's strategy for aviation would focus on meeting the needs of the entire UK and how investment in roads also benefited Scotland.
He said: "Together, we've become one of the fastest growing economies in the western world. Together, we are modernising the UK's transport infrastructure, reversing decades of underinvestment, linking up the country to secure long-term growth, and rebalance our economy.
"I don't believe that creating an unnecessary international border, where movement by road, rail, sea and air has to be controlled is the best way forward for Scotland or the UK.
"We have a fantastic opportunity here to put the difficulties of the past behind us and build a better future."
A Scottish Government spokesman said: "Direct infrastructure investment by the Scottish Government to reverse decades of neglect shows record levels of funding, with £8 billion committed over the next two years.
"We are spending more than double per head of population on our railways than Westminster over the next five years and we are taking a distinctly different path to ensure rail travel is affordable by regulating more fares and capping increases at or under inflation.
"With the powers of independence, Scotland could turn the tide on the slow progress from Westminster which too often hampers our transport decisions."
Meanwhile, the leader of Scotland's shipping industry questioned how the country's maritime sector would fit into an independent Scotland.
Ken MacLeod, president of the UK Chamber of Shipping, said: "Time is running out. This is real. We need to know in detail how independence would work so that Scottish shipping can at least have some certainty."
The SNP's White Paper on independence said shipping-related regulatory and administrative agencies would continue to be "funded by existing arrangements" by all UK taxpayers. The bodies include the Northern Lighthouse Board, which has responsibility for lighthouses on the Scottish coastline, the Maritime Accident Investigation Board, which handles shipping accidents, and the Maritime and Coastguard Agency.
Mr MacLeod, chairman of Stena Line, said: "It is clear to me that the Scottish Government has not yet done enough to explain what independence looks like for the shipping sector."