House investigators want to know when President Obama realized he could not uphold his repeated promise that "if you like your doctor, you will be able to keep your doctor" under the new health care law.

House Government and Oversight Committee Chairman Darrell Issa, R-Calif., on Monday wrote to 15 insurance companies, including Aetna, BlueCross BlueShield and Cigna, demanding by Dec. 13 "all communications" between company employees and the Obama administration dating since March 2010, when the health care reforms became law.

Issa said in the letter that millions of dropped health care plans, followed by the news of limited access to doctors under the health care law, "raise serious questions as to the origin and nature of the president's assurances."

Obama repeatedly pledged that people could keep their insurance plans as well as their doctors under the Affordable Care Act. But since Oct. 1, when the new health care exchanges opened, millions of individual policy holders have received cancellations notices and many are finding out their doctors are no longer included in their coverage.

Issa's letter to the insurers highlights a page on the government's Affordable Care Act website that promises "health insurance reform will not affect the choice of doctors you have today and it won't affect your relationship with your doctor."

But many insurers have cut the number of providers they offer to control costs under the new law, which expands benefits and allows people with pre-existing conditions to sign up.

Issa's office wants insurers to document all plan cancellation notices each sent to policy holders as a direct result of the health care law, as well as any provider cancellations.

Did the insurers try to warn Obama about the impending cancellations and changes to coverage? Issa wants to know that, too.

His request includes all documents showing "whether employees or agents" of the insurance companies objected to the administration's claim, either within the company or to the administration.

The top Democrat on the Oversight Committee, Rep. Elijah Cummings, of Maryland, accused Issa and the GOP of trying to take down the law.

“It seems like House Republicans are turning the Oversight Committee into the Repeal Obamacare Committee," Cummings said in a statement to the Washington Examiner."If the Committee spent just a tenth of the energy we now spend on tearing down the Affordable Care Act on educating and informing people about the program, we could help millions of people enroll and obtain quality affordable health insurance, many for the first time.”