Basically because they brought their extremely unpopular chairman out of hiding. Now that the voters are more exposed to her, they are running away. Add to this that they have launched a joint soc dem-green-left part election platform, which means the voters are reminded that by voting for the soc dem they are also voting in (former, or as late of 2005) communists in government. I have friends who might very well vote for the soc dems, but absolutely hate communists and would rather vote for the right.

Peak oil is not an energy crisis. It is a liquid fuel crisis.