A number of senior union figures have said that a double dissolution election would be bad for the progressive side of politics. It may be, but it is more likely that a half-Senate election would result in the conservative side of politics controlling the Senate. A double dissolution election, however, gives the progressives a better chance.
Some unionists argue that, in the event of a double dissolution, some or all of those crossbenchers who have voted against the Turnbull-Abbott government would lose their seats -- presumably to be replaced by Coalition senators. Senators Glenn Lazarus and Jacqui Lambie however, with the lower double dissolution quota, may poll well enough to hold their seats, or they could be won by a Labor or Greens candidate.