A US House panel has approved a defence bill which contains a clause to delay the lifting of the ban on openly gay soldiers.

The House Armed Services Committee voted 33-27 to approve an amendment requiring the chiefs of all four military services to certify that the change won’t hurt military readiness, AP reports.

The law to repeal the policy only requires the president, defence secretary and joint chiefs of staff chairman to certify it will not harm the military.

However, Republican lawmakers argued that President Obama has never served in the military, Admiral Mike Mullen has never served in ground combat and defence secretary Robert Gates was a political appointee.

It is not clear what effect the amendment will have. Earlier this year, all four chiefs testified that that they were not seeing issues with the lifting of the ban.

President Obama signed a law to repeal the 1993 ban in December.

The ban will not be lifted until military chiefs have certified that repealing the law will not harm military readiness. Following this, 60 days must pass. It is expected the policy will end in the summer.