Andy Coulson's warning that the UKIP leader has a "bit of a point" when he demands to be included highlights Cameron's dilemma.
Both leaders have a shared political interest in avoiding the party splits that a new vote on military action would cause.
Cameron's decision to take intervention off the table means Miliband will never have to decide whether to support military action.
PM says there will be a vote on Thursday on a government motion on UK action in Syria.
Shadow foreign secretary says he is "unconvinced" of the case for an air campaign and criticises William Hague for "implying force is inevitable".
If they want to avoid another hung parliament, both sides need to take more risks. This isn't a time for small-ball politics.
History shows that parties can win despite the unpopularity of their leaders, but to do so Labour needs to offer policy substance.
Fifty seven per cent of voters "dislike" the party compared to 43% who dislike Labour and 47% who dislike the Lib Dems.
The latest donation figures show the party was given £1.04m from donors who attended private dinners with David Cameron and other senior Conservative ministers.
In 1997, the Tories enjoyed a 22-point lead over Labour on "managing the economy" but with growth restored, voters decided it was safe to change captain.