The new policy -- issued with little fanfare this fall by the White House ethics counsel -- may turn out to be the most far-reaching lobbying rule change so far from President Obama, who also has sought to restrict the ability of lobbyists to get jobs in his administration and to negotiate over stimulus contracts.
The initiative is aimed at a system of advisory committees so vast that federal officials don't have exact numbers for its size; the most recent estimates tally nearly 1,000 panels with total membership exceeding 60,000 people.
Under the policy, which is being phased in over the coming months, none of the more than 13,000 lobbyists in Washington would be able to hold seats on the committees, which advise agencies on trade rules, troop levels, environmental regulations, consumer protections and thousands of other government policies.