President Barack Obama threatened on Tuesday to veto a major cybersecurity bill unless Congress amends it to include more protections for privacy and civil liberties.

The veto threat comes just a day before a possible vote in Congress on the Cyber Intelligence Sharing and Protection Act of 2013, or CISPA. The bill aims to make it easier for companies to share information about cyberattacks with other companies and the government.

While large tech companies have been pushing for the legislation amid escalating attacks on computer networks, privacy activists have been campaigning against it, contending it absolves companies of too much while failing to offer safeguards that protect personal information.

After the bill passed the House Intelligence Committee last week, the Obama administration signaled that it had concerns about the bill, but stopped short of issuing an outright veto threat.

But with the bill scheduled for vote either Wednesday or Thursday in the U.S. House of Representatives, the Obama administration issued a "Statement of " on Tuesday from the Office of Management and Budget saying the bill needed to be amended or else face a veto.

In addition to better , the statement calls for further changes to reflect that information about such breaches would be handled by civilian agencies rather than the military, and that exemptions from legal liabilities would be much narrower.

The statement cheered privacy activists who have been leading online organizing efforts for several weeks.

"As technology changes we must not allow our constitutional protections to be eviscerated. CISPA represents a threat to the freedom of all Americans who believe in the value of the Bill of Rights," David Segal, executive director of Demand Progress, said in a statement. "We are heartened that President Obama has heard our call and acted in the best interest of the American people."

The immediate effect of Obama's statement on the looming vote is unclear. Last year, the House passed a similar bill despite a veto threat from Obama, but the legislation failed to gain any traction in the U.S. Senate in 2012.