1) The radical nutjobs in his own ranks gunning for him.
2) He's starting from a long way behind (in terms of the number of seats).
He knows that he has to appeal to the middle ground in order to stand a chance of forming Government.
However, in doing so he risks galvanizing the (unelectable) far right in his party, who will redouble their efforts to destabilize the Party and get rid of him.
