No, once the Patent Office determines that a patent application contains two separate and distinct inventions, the parent application and its subsequently-filed divisional application are immune from a challenge of double-patenting. 35 U.S.C. 121. If the law were otherwise, this would be manifestly unfair to the patentee: the USPTO could first issue a restriction, claiming the patent application contained two "separate and distinct" inventions. This would require the patentee to withdraw a subset of his claims and file them in separate divisional application. Then the USPTO could reject the divisional application in view of the parent application on the grounds of double-patenting.