The White House on Monday defended President Barack Obama's support for taxing high-value insurance plans to pay for covering millions of uninsured Americans.

The president is scheduled to meet with labor leaders on the issue Monday afternoon. Labor opposes the tax, arguing it would hurt union members who negotiated good health benefits instead of salary increases.

At his daily press briefing, White House spokesman Robert Gibbs disputed that the insurance plan tax is similar to what Republican John McCain proposed while running against Obama for president.

McCain wanted to eliminate tax-free health benefits altogether. The plan Obama supports, which is part of the sweeping health care bill passed by the Senate, would tax insurance companies on plans worth more than $8,500 for individuals and $23,000 for families.

The approaches are "fundamentally different," Gibbs said. Labor leaders say they aren't so different, arguing that the tax on so-called "Cadillac" insurance plans would get passed down to working people.

Gibbs also indicated that Obama is open to adjusting the tax so it would affect fewer people. He said that would be discussed at Monday's meeting with about a dozen major union heads.

The insurance plan tax is one of the sticking points between House and Senate Democrats as they work to reconcile health legislation passed by each chamber. They're looking for a product that Obama could embrace and sign into law in time for his State of the Union address sometime next month.

Many House members oppose the insurance plan tax. Their bill would raise income taxes on high-wage Americans instead.

But with Obama behind the Senate's insurance tax — which the president contends would help reduce spending on health care, one of his top goals — the final bill will likely include it in some form.