President Obama vetoed a bill Friday aimed at repealing his signature health care law.

"This legislation would not only repeal parts of the Affordable Care Act, but would reverse the significant progress we have made in improving health care in America," the president wrote members of the House in a letter.

"Republicans in the Congress have attempted to repeal or undermine the Affordable Care Act over 50 times. Rather than refighting old political battles by once again voting to repeal basic protections that provide security for the middle class, members of Congress should be working together to grow the economy, strengthen middle-class families, and create new jobs," the letter continued. "Because of the harm this bill would cause to the health and financial security of millions of Americans, it has earned my veto."

The president's veto comes after the House's recent passage this week almost entirely along party-lines, 240 to 181, to repeal the Affordable Care Act and defund Planned Parenthood. Just one Democrat voted for the bill and three Republicans voted against it.

The Senate passed the Restoring Americans' Healthcare Freedom Reconciliation Act in December. It was successful because Republicans used the process of budget reconciliation that prevented a filibuster by Senate Democrats.

Related: Congress Sends Obamacare Repeal to President for First Time

Since the law's passage, Republicans in Congress over the past few years have authored dozens of unsuccessful attempts to repeal all or part of the health care law. Repealing the president's landmark accomplishment continues to be a rallying cry for the GOP and House Speaker Paul Ryan has vowed to continue the effort.