President Obama is unlikely to offer the dramatic overhaul demanded by critics of National Security Agency surveillance techniques on Friday, as he tries to appease both defense hawks and civil liberties groups in one of the most anticipated speeches of his presidency.

Instead, the president will shift the debate over the hotly-contested spying practices to Capitol Hill, according to intelligence, congressional and administration officials.

At the Justice Department on Friday, the president will announce modest changes for clandestine techniques exposed in leaks by former government contractor Edward Snowden. He will also defend the importance of preserving data-collection techniques he contends protect the homeland, leaving Congress to answer the most far-reaching questions surrounding the secretive spy agency.

Critics of the NSA expect that Obama will merely punt to lawmakers, letting Capitol Hill debate how government should store Americans' information. They say the speech will highlight his evolution from an unabashed reformer on privacy rights to a commander in chief whose views have been hardened by the daily intelligence briefings unique to his office.

As the president is well aware, his NSA blueprint will likely leave both progressives and civil libertarians wanting more.

“It's like the White House is just handing us a live grenade,” complained one senior Democratic Senate aide. “There's a lot of people over here who wish he would be more bold.”

The NSA will continue to store massive amounts of U.S. phone data, Obama will announce, resisting the recommendation of an outside panel to have either a third-party or phone companies keep the metadata, sources say.

This issue will likely become the centerpiece of how Congress ultimately decides to move forward on the NSA.

Obama also will not heed calls for the government to get a court order each time it wants to obtain phone records as part of an investigation, according to sources familiar with the president's plan.

The White House has indicated, however, that Obama is open to reduced spying on foreign heads of state.

German Chancellor Angela Merkel ripped into Obama when it was revealed that U.S. officials were tapping her cellphone; Brazilian President Dilma Rousseff also pulled out of a planned state dinner at the White House after learning of the U.S. monitoring her personal communications.

Obama has also already signaled that he supports the idea of a privacy advocate to argue before the secret surveillance court.

Yet, even that proposal created immediate blowback from the federal judiciary.

"The participation of an advocate would neither create a truly adversarial process nor constructively assist the courts in assessing the facts," said U.S. District Judge John D. Bates, who was previously a judge on the Foreign Intelligence Surveillance Court.

Given Obama's growing reliance on executive actions -- on issues ranging from the environment to immigration and Obamacare -- some noted the irony of him leaving the NSA issue mostly to Congress.

“Guess this isn't part of the 'year of action,' " quipped one House GOP aide, mocking the latest White House slogan.

Privacy advocates, pointing to Obama's pledge to run the most transparent administration in history, have also already begun voicing their disappointment ahead of the president going public with his plan.

“President Obama's trajectory on these issues … has been very dispiriting,” said Kevin Bankston, policy director of the New America Foundation’s Open Technology Institute. ”I think it highlights how often those who are charged with oversight of these programs … become the cheerleaders for the intelligence community.”

“It is impractical to assume the executive branch will hold itself fully accountable,” added Angela Canterbury, director of public policy for the non-profit Project on Government Oversight and Accountability. “Perhaps the president's tepid proposals will galvanize [Congress].”

The uproar over the NSA surveillance methods has united the progressive wing of the Democratic Party and libertarian-leaning Republicans unlike any issue in recent memory. A bipartisan coalition exists to move forward on legislation but leadership in both chambers has been noncommittal on new laws ahead of the president's remarks.

However, the president's own lofty rhetoric about not sacrificing privacy in the name of national security created a high bar for his reforms.

“We are at a very historical moment right now,” said Michelle Richardson, legislative counsel for the American Civil Liberties Union.”Will the government continue to spy on everyday Americans?"