House lawmakers wrapped the first secret session in 25 years Thursday night to discuss the terror surveillance bill and plan to open debate and possibly vote later this morning.

GOP representatives were hoping to sway House Demcrats against moving forward with their version of the legislation, which the White House has threatened to veto.

"I'm glad the majority joined us in allowing this serious discussion, " said House Minority Whip Roy Blunt after the session. "Based on the intelligence offered tonight, there are very powerful reasons why we must pass the bipartisan Senate bill."

Many Democrats initially objected to the secret meeting, calling it a political ploy by Republicans to delay the vote.

Republicans argued, though, that they have relevant information for the debate that can only be considered in closed session — House Majority Leader Steny Hoyer agreed to the request by Blunt.

Only members of Congress and some staff were allowed to attend and time was believed to be split between Hoyer and House Minority Leader John Boehner. They are not allowed to divulge activities that go on during these secret sessions, and are required to sign a special oath that they won't divulge what's discussed during the meeting.

The press and the public were banned from the sessions, and the doors were locked hours earlier to allow for a security sweep. Lawmakers were asked to deposit their phones, pagers and BlackBerries in sealed yellow envelopes which were then stowed in large milk crates outside the sealed House chamber.

Capitol police moved all press off the second floor area surrounding the chamber where the closed session was held.

The closed sessions are most often held to discuss national security. The last such session in the House was in 1983 on U.S. support for paramilitary operations in Nicaragua. Only five closed sessions have taken place in the House since 1825.

No secret sessions occurred between 1830 and 1979.

Speaking of the decision to hold a secret session, House Judiciary Committee Chairman John Conyers said the more information lawmakers get on the eavesdropping programs, the less fearful they are of scare tactics. He said the administration has not made the case for unprecedented spying powers and blanket retroactive immunity for phone companies, the two key prongs of the terror surveillance legislation.

"Whether this is a worthwhile exercise or mere grandstanding depends on whether Republicans have groundbreaking new information that would affect the legislative process," Conyers said. "There must be a very high bar to urge the House into a secret session for the first time in 25 years. I eagerly await their presentation to see if it clears this threshold. As someone who has seen and heard an enormous amount of information already, I have my doubts."

A previous bill was passed temporarily in August, and its expiration was pushed back once already as lawmakers debated which tools are essential to intelligence agents listening in on suspected terrorists.

President Bush issued a new veto threat on Thursday against the House Democrats' version of the bill, which he says would undermine the nation's security because it would offer no protections to telecoms that help the government with phone numbers.

"The American people understand the stakes in this struggle. They want their children to be safe from terror," Bush said. The House bill "could reopen dangerous intelligence gaps by putting in place a cumbersome court approval process that would make it harder to collect intelligence on foreign terrorists."

Article I, Section 5 of the Constitution allows for closed sessions of both the House and Senate. While all closed sessions are rare, they are particularly unique in the House.

Over the past few days, House Republicans have forced a variety of parliamentary votes to protest how Democrats have handled the terror surveillance issue. Boehner, R-Ohio, said Republicans want to make sure Democrats have the classified information they frequently claim to lack when it comes to making decisions on this legislation.

"Democratic leaders cannot hide behind these excuses any longer. We must give our intelligence officials all the tools they need to keep the American people safe, as well as protect patriotic third parties who have helped us defend this country since 9/11. Its our hope that members will come away from this briefing with a better understanding of how important these programs are for the safety and security not only for the American people, but our soldiers on the ground in Iraq, Afghanistan and elsewhere around the world," said Boehner.

At a press conference Thursday, House Speaker Nancy Pelosi said she was willing to listen to the case Republicans are presenting so she could make an informed judgment on the legislation.

"If there is some merit to having a closed session that is worth pushing back consideration of the bill, let's hear what their purpose is," she said.

FOX News' Chad Pergram and The Associated Press contributed to this report.