Tony Abbott is dreaming if he thinks the threat of a double dissolution will stop the current Senate voting against his proposed legislation on abolishing a fixed price on carbon.
( There is the question on whether he could call one anyway. see link at the bottom of the page.)
Imagine he did call a double dissolution.
This would mean the next half senate election would be out of kilter with the house of representatives.
He then would either :
1) have to have a separate half senate election and hope history does not repeat itself. The last time this occurred in 1967 there was a massive swing against the government. The electorate simply made it into a large by-election or
2) have an early election combining the house of representatives and the half Senate as normal. how do you think punters out there would like to have have not one but two early elections?
That is why Tony Abbot is dreaming. Just remember it looks likely the new Senate in July will pass his legislation so the threat then looks even more shallow.
See Here for an interesting paper on double dissolutions courtesy of Antony Green.
Here is MUMBLE