How to vote anti-war?

Some people favour voting for something you don't want in the coming election on the grounds that you can't vote for what you do want (or that this has no chance). One such group is Strageic Voter which aims to "hold New Labour to account for the illegal invasion of Iraq" by unseating MPs who voted for it. On their website (www.strategicvoter.org.uk) they make recommendations constituency by constituency "to steer towards a balanced (or 'hung') Parliament. We want to punish the government, but not finish up with a Tory majority either".
On Vauxhall, they say:
"A special situation makes this seat hard to categorise.
The following discussion relates specifically to this constituency
We apologise to our visitors and the Labour candidate for having given poor advice in this seat but trust that it is sorted out now (March 15th). Thanks to those who pointed out the problems.
Here we have a candidate from a pro-war party who deserves immense credit for resisting the party line and voting against the illegal invasion of Iraq. However they are being opposed by someone from an antiwar party who may have been active in the antiwar movement and may well also have voted against the war. You may want to take their respective position on other issues into account. StrategicVoter does not have strong views, just so long as a pro-war candidate isn't returned."
This is all rather cryptic. Who is this mysterious candidate who may oerhaps have done various things if they had had have been an MP? And which party are they standing for? Our interpretation (and we may be wrong, not having any qualifications in interpreting oracles) is that they are trying to say that if you are anti-war (or rather against "the illegal invasion of Iraq") you've got a free hand in Vauxhall.
For the record, we in the Socialist Party only want the votes of those who want socialism (a worldwide society of common ownership and democratic control where things are produced to meet people's needs not to try to make a profit). If you are just against "illegal" wars and would be in favour of a "legal" one; if you are against war but not against capitalism (i.e., are against the symptom but not against the cause); or if you want a hung parliament and a resulting coalition government for British capitalism, please feel free to vote for one of the other candidates. But, be warned, in voting for them you'll be voting for capitalism and capitalism is the root cause of wars, preparations for war and threats of war because built-in to it are conflicts between rival groups of capitalists backed by their governments over sources of raw materials, trade routes, markets and investment outlets. Normally, this competition is commercial and diplomatic but, when push comes to shove, the conflicts are settled by forces of arms. This is why Britain and America (or, rather, America and Britain) invaded Iraq where the former regime represented a threat to their supply of oil, a key raw material. Capitalism means war, so the only consistent anti-war stance is to work to get rid of capitalism.