WASHINGTON  Calling into question the legitimacy of all the signing statements that former President George W. Bush used to challenge new laws, President Obama ordered executive officials on Monday to consult with Attorney General Eric H. Holder Jr. before relying on any of them to bypass a statute.

But Mr. Obama also signaled that he intended to use signing statements himself if Congress sent him legislation with provisions he decided were unconstitutional. He promised to take a modest approach when using the statements, legal documents issued by a president the day he signs bills into law that instruct executive officials how to put the statutes into effect. But Mr. Obama said there was a role for the practice if used appropriately.

“In exercising my responsibility to determine whether a provision of an enrolled bill is unconstitutional, I will act with caution and restraint, based only on interpretations of the Constitution that are well-founded,” Mr. Obama wrote in a memorandum to the heads of all departments and agencies in the executive branch.

Mr. Obama’s directions were the latest step in his administration’s effort to deal with a series of legal and policy disputes it inherited from the Bush administration. They came the same day Mr. Obama lifted restrictions Mr. Bush placed on federal financing for research that uses embryonic stem cells.