Election time is here again and the manifestos should soon be out with their strange mixture of actions the various parties want to take and promises they hope they won’t have to deliver.

My special request to the SNP is to just leave it on constitutional change - we have had enough to last us a lifetime and the economy does not need more uncertainty. Concentrate instead on real things.

For the Greens, just do your stuff. If we did everything you said our economy would be in ruins but there is an environmental problem and your influence on that is important and positive.

For the Brexit party - please just go away.

What about the rest though? Those who might have power, Conservative, Labour, even the LibDems. The parties which believe in the Union.

What these parties should be asking themselves is why such an economically daft idea as Scottish Independence has gained traction with a sizeable minority of our electorate. Promises which cannot be kept, real and adverse impact on public services, major damage to our economy - all glossed over by the Nationalists and swallowed by their followers.

Why? In large measure it is because voters have not had a good decade.

Real incomes have stagnated, uncertainty has increased. This is fertile ground for those like the SNP who advocate major change, who blame external factors for all ills and who promise an easy fix - place your tick here and all this pain will be over. The benefits of the Union - which is actually providing funding for our schools and the largest market for our goods are all around us but seem invisible.

What the Unionist parties could do is tackle two problems head-on. The obvious issue is inadequate infrastructure, the perception issue is that the benefits of the Union are inadequately perceived. An election is an opportunity to change that.

If the Unionist parties want to go on the offensive rather than constantly defend they need to lay out some bold plans in their manifestos for this election.

Let me give them some suggestions.

First the South of England has to take some pain - that region has such huge economic privileges that it simply cannot be allowed to be the focus of our next great National Infrastructure projects. The projects which should be cancelled or deferred are Crossrail 2 (£30 billion), HS2 (£80 billion and rising) and the new runway at Heathrow (£14 billion).

What should be developed in their place are new projects which benefit the wider country away from the South-East of England, provide significant economic impetus to those regions, connect up the United Kingdom better and demonstrate in a real and practical way the benefits of the Union.

Not all of these should be in Scotland. For example, the North of England is crying out for its own Crossrail providing fast rail services from Liverpool to Hull via Manchester and Leeds.

I can think of three obvious projects which would benefit Scotland.

First, a commitment to invest quickly so that by the end of the next Parliament trains are regularly running between Glasgow and London in less than 4 hours.

Second, dual the A1 right up to the Scottish border.

Third, build a bridge between South-West Scotland and Ulster. This would transform the economies of those areas and nothing could symbolise better the benefits of the Union and the economic strength it has. The fact that this project is difficult and expensive is a plus not a minus, the Union needs to do something hard not something easy to demonstrate its worth.

Guy Stenhouse is a Scottish financial sector veteran who wrote formerly as Pinstripe.