CL is currently getting child increase on incap. Change of circumstances so moving to tax credits- will he definately lose child increases or is there any way of protecting them?

Not a definate answer I'm afraid, but I briefly looked in to this issue a few weeks ago when someone came to see me who was receiving both a dependant addition on his Incapacity benefit and maximum child tax credit, and I wondered if he may be being overpaid. I didn't look behond CPAG and Disability Rights, but both of these seem to suggest that both can be paid together in that they don't say anything specific to the contrary. Someone else may have a more definitive answer?