THIS Tuesday I will visit Brussels to deliver my first speech in the EU capital since becoming First Minister.

At heart, my message will be a very simple one; namely that Scotland is a European nation and that my government sees our future as one of continued European Union membership. The importance of this message to our economy and future prosperity cannot be overstated.

It will also be an important counterpoint to the message David Cameron is seeking to deliver in his round of shuttle diplomacy between European capitals, as he seeks to "renegotiate" the terms of the UK's EU membership in ways which remain obscure, and in talks in which even the Prime Minister seems unsure what would constitute success.

It is important that our friends and neighbours in other European countries hear a counterbalancing narrative, and understand that there are those in the UK who are positive and constructive about how we can work together, and crucially, about how we can make the EU itself work better for its citizens.

That is not to say that I or the Scottish Government consider the European Union to be perfect - we don't. Like all governmental institutions, it needs to constantly evolve to ensure it properly serves ordinary people.

For example, there have long been concerns in Scotland, shared on a cross-party basis, about the direction of the Common Fisheries Policy. On public health policy, the EU institutions need to do more to recognise the human costs of inaction.

So on these, and on other issues, we will continue to make the case for sensible reform, working alongside our partners from other countries to find common ground.

And that is the key distinction between ours and the UK Government's approach to Europe. It is possible to seek reform in partnership and without rancour. Unfortunately, David Cameron's approach is more akin to demanding special treatment and threatening to walk out and slam the door behind him if he doesn't get what he wants.

The greatest irony in this debate however, is that Mr Cameron himself appears to have been dragged to a place which is at odds with his own instincts and beliefs. And he has been taken there by a deep vein of Euroscepticism within the Tory party which has festered for more than two decades, and which now has the toxic rhetoric of UKIP added to the mix.

The truth is that, for a very sizeable chunk of Mr Cameron's Tory colleagues in Westminster - and perhaps for an even bigger proportion of the Conservative party's grassroots - no reform, no renegotiation and no repackaging of Britain's EU membership will be good enough. Because these are people who do not want reform, they want out. And for them, only "out" will do.

So the Prime Minister is not in control of events on this, the biggest single issue set to dominate UK politics for the next year or two. He is beholden to those in his party for whom no renegotiation will be deemed sufficient or acceptable, at the same time as not being able to predict or control what governments and leaders from the other 27 EU states may say in response to his demands.

That is a highly combustible mix and shows that, whatever he claims, Mr Cameron really doesn't know where this will end.

The Prime Minister wants to be able to present a package of measures which he can claim as a major victory in the renegotiation stakes and then aim to swing his government firmly behind a "Yes" vote for the UK to stay in Europe.

But what if the package doesn't stand up to scrutiny? What if other major European leaders decide they cannot play along? What if his own party lurches into open warfare with senior figures, including current cabinet members, openly calling for an "out" vote?

At that point, all bets on the UK's future in the EU are off. And it doesn't take too much imagination to see David Cameron becoming engulfed in a crisis on Europe that makes John Major's Maastricht travails look utterly trifling in comparison.

All of this is deeply troubling to those of us who want to see Scotland and the UK remain in Europe.

For all its imperfections, the EU is of huge benefit to Scotland, with around 330,000 jobs here dependent on our membership of the single market. Just this week we had new figures confirming Scotland's pre-eminence as a destination for foreign investment - a position that would be severely threatened by our withdrawal from the EU.

Scotland is an ancient European nation, and - as I will make clear in Brussels this week - I passionately believe our future is as part of the modern European family of nations.