Heading into a critical week, the White House is magnifying its lobbying efforts on a handful of senators who hold the key to creating President Bush's Department of Homeland Security.

Bush met Friday at the White House with Sens. Phil Gramm, R-Texas, and Zell Miller, D-Ga., to discuss how to win over GOP Sen. Lincoln Chafee of Rhode Island and Democratic moderates on the central issue of labor rights for the proposed agency's 170,000 employees.

Gramm and Miller are sponsoring a new legislation that attempts to bridge the gap between Republicans and Democrats, who largely oppose Bush's demands for the ability to implement a new personnel system in the agency and waive union job rules for reasons of national security. Bush has threatened to veto a Democratic bill that does not include those powers.

After three weeks of debate, the dispute is expected to come to a head next week in a Senate almost evenly divided between Republicans and Democrats who are anxiously eyeing the Nov. 5 elections.

The intensified lobbying campaign is expected to include telephone calls from Bush himself as well as calls and personal visits from Cabinet members and Tom Ridge, the White House homeland security chief, according to a congressional source who attended the White House meeting and spoke on condition of anonymity.

The arguments being made by Bush and his allies are that the union waiver authority is identical to that available to every White House since President Carter -- authority Democrats want to take away -- and that it is bad politics to oppose the president for reasons of union allegiance when the United States is in a war against terrorism.

"For the life of me, I cannot understand why some of my colleagues want to fixate on workplace rules, procedures, and regulations and protecting workers' rights instead of protecting Americans' lives," Miller said after the White House meeting.

Besides Chafee, senators identified as crucial votes are all Democrats: John Breaux and Mary Landrieu of Louisiana; Max Cleland of Georgia; Ben Nelson of Nebraska; and Jean Carnahan of Missouri. All but Breaux and Nelson face re-election on Nov. 5, and those two are moderates who do not always toe the Democratic line and have been shopping around their own suggested compromise.

Another fence-sitting Republican, Sen. Susan Collins of Maine, said Friday she will support the Gramm-Miller bill after the sponsors included language guaranteeing certain Coast Guard missions will continue in the new agency. She also received a written pledge from Ridge that Bush will not try to use the union waiver authority to remove large numbers of homeland security employees from collective bargaining.

"This letter is a very strong statement that he will not do that," Collins said.

Bush planned to use his Saturday radio address to increase pressure on the Senate to approve a bill he can accept, said White House spokesman Ari Fleischer.

"The president hopes that it won't be a fairly partisan vote and he hopes that more Democrats will join with their colleague, Senator Miller, so that won't be the case," Fleischer said. "But what's important is for the Senate to act."

Supporters believe that once it becomes clear the Homeland Security bill will pass, they will gain more votes from Democrats who don't want to be seen as opposing the president on the issue.

Miller said he has been arguing with party leaders that Democrats will not be forgiven by voters if they oppose Bush on the bill, even if they later vote in favor of using military force against Iraq.

The chief sponsor of the Democratic bill, Sen. Joseph Lieberman of Connecticut, sounded a conciliatory note Friday, telling reporters that the Gramm-Miller bill appeared "very encouraging" because it was similar to his bill in areas such as intelligence analysis.

Lieberman quickly added there remained "the significant difference" between the two parties on worker rights but expressed hope a compromise could be reached. He said he had spoken Friday with White House Chief of Staff Andrew Card in one of the "good, sincere discussions" that were going on.

"I find myself to be surprisingly encouraged," Lieberman said.