Late Tuesday afternoon, House Republicans unveiled their plan to improve on the Senate bill providing tax relief to low-income families.

Ways and Means Chairman Bill Thomas (R-Calif.) derided the Senate’s bill as his party’s leadership met with White House officials to sell them on the plan.

“We’re not in the business of politics but rather of policy,” said Thomas, whose bill is scheduled for floor action Thursday.

While the Senate provision focuses on families earning between $10,500 and $26,625 — giving them a refund if they have no tax liability — Thomas’ plan would do a number of things.

For instance, it would increase the child tax credit to $1,000 through 2010 and raise to $150,000 the amount that can be earned by couples who use the child tax credit.

“If these people need help, they need it for the rest of the decade,” Thomas said, explaining why his plan extends longer than the Senate version.

The Senate bill would cost about $10 billion and is offset. Thomas’ bill would cost about $80 billion, with no offsets.

“Politics is always cheap,” Thomas said, defending why his plan costs more.

The Senate stripped an unrelated House bill to insert its own text —as revenue measures must originate in the House — when it passed its version June 5.

Thomas has salvaged one of those provisions in his package: The families of astronauts who died in the space shuttle Columbia disaster would be extended the same special tax relief granted to those who lost family members in the Sept. 11, 2001, terrorist attacks.