A PLAN to display Union Jack flags on roads, bridges and other publicly funded infrastructure projects across Britain has been branded a “silly gimmick”, even before its official launch.

Danny Alexander, Chief Secretary to the Treasury, said the plaques featuring the message “Funded by UK Government,” would “proudly adorn infrastructure investments from roads in Cornwall to broadband in Caithness”.

But SNP deputy leader Stewart Hosie said they would not disguise the coalition’s cuts to overall infrastructure spending and Scotland’s capital budget.

He said: “Putting a sticker on projects is a silly gimmick by Danny Alexander and his Tory bosses, which can’t cover over the fact that his government at Westminster has slashed infrastructure spending – destroying jobs and delaying economic recovery – including cutting Scotland’s capital budget by a quarter.

“Instead of the huge cuts imposed by Danny Alexander and the Tories, people across the UK would prefer more infrastructure investment, and fewer gimmicks.”

Alexander, who will detail the plan on a visit to south-west England today, said: “I’ve prioritised infrastructure in this government because only long-term investments will support UK businesses and get the public finances and economy on a firm footing.

“It’s only right that we recognise the contribution of the UK taxpayer in supporting this economic growth, which is why I’m delighted to launch these Union Jack plaques, which will proudly adorn infrastructure investments from roads in Cornwall to broadband in Caithness.”

The plan has been drawn up with Cabinet Office minister Francis Maude, who added: “As part of our long-term economic plan, this government is investing in our nation’s physical and digital infrastructure.

“Whether it’s High Speed 2 investment in the northern powerhouse or superfast broadband connecting Cornwall and Wales, all future infrastructure projects funded for by UK taxpayers will carry this simple UK flag branding.”

Under Alexander’s plan, any firm that wins a UK Government contract will have to agree to display the logo on the finished work. It copies a long-standing Brussels agreement that sees the EU flag displayed on infrastructure it has funded. But Scottish nationalists are likely to see the plaques as a deliberate attempt to shore up support for the union.

Ministers are concerned about the rise in support for the SNP since the independence referendum in September, when nearly half (45 per cent) of voters backed a breakaway from the union.

Since then the SNP has seen its membership and support soar and, with Scottish voters set to play a decisive role in the General Election, the plaques could be seen as a move to counter that surge.

In the event of a hung parliament Labour may have to depend on nationalist MPs for support, raising the prospect of a second independence referendum.

According to the Treasury there are £466 billion of new projects in the pipeline, many of which the government is funding with public money.

Last week, the secretary general of the Organisation for Economic Co-operation and Development praised the UK’s investment in infrastructure and called on the government to “continue to build on the progress made with the National Infrastructure Plan” to ensure that the UK’s “textbook” recovery continues.

In 2012 a similar logo was introduced for foreign aid funding, which included the Union Flag and the words “UK aid from the British people”. Its use is not optional, but a condition of accepting funding from the Department for International Development.