WASHINGTON — President Barack Obama, strategizing Friday with congressional leaders about health-care reform, complained that liberal advocacy groups ought to drop their attacks on Democratic lawmakers and devote their energy to promoting passage of comprehensive legislation.

In a pre-holiday call with a half-dozen top House and Senate Democrats, Obama expressed concern over advertisements and online campaigns targeting moderate Democrats, whom they criticize for not being fully devoted to "true" health-care reform.

"We shouldn't be focusing resources on each other," Obama opined in the call, according to three sources who participated in or listened to the conversation. "We ought to be focused on winning this debate."

Specifically, Obama said he is hoping left-leaning organizations that worked on his behalf in the presidential campaign will now rally support for "advancing legislation" that fulfills his goal of expanding coverage, controlling rising costs and modernizing the health system.

In the call, leaders of both chambers expressed optimism that they will hold floor votes on legislation that overhauls the $2.2 trillion health system before Congress breaks in early August.

For his part, the president vowed to use his strong approval rating with voters to continue making the case for sweeping reform, according to one congressional staffer with knowledge of the conversation. Obama also hinted that efforts are under way to discourage allies from future attacks on Democrats, according to the source, who did not have permission to speak on the record about the discussion.

The White House had no comment on the president's call.

In recent weeks, liberal bloggers and grass-roots groups such as Moveon.org, Democracy for America, Service Employees International Union and Progressive Change Campaign Committee have targeted Sens. Ben Nelson, D-Neb.; Mary Landrieu, D-La.; Arlen Specter, D-Pa.; Ron Wyden, D-Ore.; and Dianne Feinstein, D-Calif.

A fundraising video produced by Democracy for America suggests Landrieu is a "sellout" because she has received $1.6 million in campaign contributions from the health-care industry and has yet to endorse the concept of a government-run health insurance plan to compete against the private companies. The public-option concept, which Obama supports, has become a litmus test for many pro-reform activists who accuse the insurance industry of failing to deliver affordable, accessible care.

"Tell Sen. Landrieu to support the people of Louisiana, not insurance companies," the spot concludes.