Operation Christian Vote
Labour: The catchline to Labour's campaign will be that Scotland and the UK is working and that the Tories must be prevented from "ruining" this.
It might be said that this is a purely negative approach.
Labour strategists justify this on the grounds that they are in the ranking position in terms of Euro MPs and the Scottish Parliament and Westminster.
Little wonder, they argue, if they act defensively.
Labour believes that the Tories want to use the Euro elections not as an end in themselves - but to consolidate the "bounce" which their party has had from the accession of Michael Howard to the leadership.
Labour will use these elections to remind voters of the Tories' record in office - while Michael Howard was a Cabinet minister. Expect to be besieged with talk of unemployment and the poll tax.
The second string to Labour's bow in these elections is more clearly European.
The party will argue that Europe is important to Scotland's interests, that leadership is required and that the only party strategically placed to deliver that leadership at the heart of Europe is Labour.
It will seek to contrast their self-proclaimed status with the Euro-sceptical stance of the Tories and, to a lesser extent, with the position adopted by the SNP.
Labour will claim again - no doubt to the fury of the Nationalists - that an independent Scotland would have to renegotiate membership of the EU.
Labour's preparation for the European campaign has been undermined by allegations against its lead MEP, David Martin, the vice-president of the European Parliament.
He has strenuously denied claims of misuse of allowances. It would appear that these claims have been pursued by the brother of Mr Martin's estranged wife.
An initial investigation by the European Parliament cleared Mr Martin. Further claims were then submitted.
Mr Martin has now demanded that the European Parliament conduct an external audit into the claims and has promised that he will stand down as an MEP if any wrongdoing is found. He re-stresses his absolute confidence that he will be cleared.
SNP: For years, the Nationalist slogan has been "independence in Europe".
That implied that rather than simply abandoning the comfort blanket of the UK, Scotland would be joining a large, international grouping in her own right.
Some have questioned whether that strategy has altered a little in the light of the Nationalists' warning that they will not endorse the new EU constitution unless control over fisheries is repatriated and the Common Fishing Policy dropped.
For myself, I believe three things: that the overall SNP strategy has not changed - "independence in Europe" remains; that the SNP has a genuine concern for the future of Scotland's fishing fleet; but that, in subterranean fashion, the party finds itself more comfortable in a political position which involves partly challenging Europe rather than endorsing it without question.
It is only fair to say that Nationalist leaders insist their position shows no change at all - that they are only standing up for a Scottish national interest in challenging Tony Blair to demand a new deal on fishing, to "red line" that issue alongside other matters which the PM says are vital to UK interests.
For these elections, the SNP says it has a campaign with three pillars - fishing; the council tax; Iraq and the issue of trust in Tony Blair.
It will be noted that these are not, strictly and purely, European questions. But see above: the voters will not tolerate a campaign of European political purity.
They want politicians to talk about their concerns. For the Nationalists, that means the fate of the fishing industry, their plan to replace the council tax with local income tax - and the war. Always the war.
Conservative: As throughout the rest of Britain, the Scottish Tories' tone is Euro-sceptical. They stress - in response to taunts from Labour - that they remain resolutely in favour of Britain's membership of the EU.
Their ambition, they say, is to rebalance power in favour of the member states and away from a "European superstate".
If their thunder was stolen somewhat by the decision to concede a referendum on the EU constitution, they attempt to regain ground by insisting that such a referendum must be held at an early date rather than, as the prime minister insists, following full consideration by the Commons of any final constitutional text.
Plus of course they intend to preview that referendum debate in these elections by arguing that the European Constitution, with plans for a standing president and an enhanced voice in foreign affairs, represent an intolerable transfer of power to Brussels.
Adding a Scottish flavour to this Britain-wide perspective, they say they would stand up for the true interests of Scotland's farmers and fishing fleet.
In Scotland, their Euro launch was rather overshadowed by a controversy dogging their most prominent MEP Struan Stevenson.
Mr Stevenson had been recorded registering for daily expenses in the European Parliament before heading straight to the airport.
He pointed out that he was simply following the rules determined by the present, unsatisfactory expenses system, a system which the Tories wanted to reform.
Liberal Democrat: While there may be a dispute about the extent of Euro-scepticism prevalent in other parties, the Liberal Democrats say they offer certainty. They insist they are the only party taking an avowedly positive line towards Europe in these elections.
They say that the future of Europe has never been closer to the political core and that this argues for support for a party which is Euro-enthusiastic. That applies to the EU constitution and other matters.
Their case is that their positive stance on Europe leave them best placed to make Europe work in Scotland's interests on issues like farming, fishing, the environment and international security.
Green: As an autonomous party, the Scottish Greens hope to join their English counterparts in the European Parliament.
Their main pitch will be the environment, arguing that the vast majority of legislation in this field affecting Scotland comes from Europe rather than Holyrood or Westminster.
On the EU constitution, they say they are not opposed to the concept in principle but have serious problems with the present draft over issues like nuclear energy.
Scottish Socialist Party: It is one of the vagaries of European politics that the status of the EU can stir up apparently comparable reactions on the right and left in domestic politics.
Thus the SSP, like the Tories, are opposed to the EU constitution - but for rather different reasons.
The Scottish Socialists say the EU is a "business club" with little real interest in the poor and that the new constitution merely entrenches that.
UKIP: The title says it all. This party stands for "UK independence", for Britain's withdrawal from the European Union.
In addition, they say they'd "put an end to mass immigration", tackle European red tape and challenge "political correctness".
BNP: The British National Party says it is standing in the European Parliamentary Elections to give a voice to the Scots who are troubled by the growing influence of the EU.
The BNP stands for British withdrawal from the EU which it says enacts "unnecessary, costly and repressive legislation into every aspect of daily life".
The party says that it is campaigning on the pressing issues of the day including crime, asylum, globalisation and the collapse of social structures such as the family, "without the constraints imposed by political correctness".
Scottish Wind Watch: Scottish Wind Watch is opposed to "environmentally insensitive" wind-power schemes which it says are likely to be damaging to landscape, wildlife habitats, historic sites, and public enjoyment of the countryside.
It sees the European election as an opportunity to gain national coverage for the wind-power issue.
It says that it wants to wake up the people of Scotland who are still largely unaware of what is being planned for its wild places.
Operation Christian Vote: Operation Christian Vote started life as a voters' registration drive among Britain's Christian community.
The decision was taken to register as a political party when it became clear that there would be no opportunity for Christians to vote according to their faith and conscience in the European elections.
It will be calling for the outlawing of abortions and human embryo research.
It also values the relationship between a man and a woman in the "covenant of marriage, over and above any other domestic arrangement".