House Freedom Caucus Chairman Mark Meadows (R-N.C.) said he wants Congress to enact a corporate tax rate that’s in the teens in order to go “big and bold” on tax reform.

“I don’t want to nibble around the edges,” Meadows said Wednesday at an event hosted by Americans for Prosperity (AFP), a group backed by the GOP mega-donors Charles and David Koch.

“I think that something with a one in front of it, whether it’s 15 or 17 or 18 [percent], that’s where we need to be,” he added.

{mosads}Republicans broadly agree about wanting to lower the corporate tax rate, which is currently 35 percent, but they don’t have consensus on what the new rate should be.

While the White House is aiming for a corporate tax rate of 15 percent, Senate Finance Committee Chairman Orrin Hatch (R-Utah) said that rate is unlikely and that it would be challenging to lower the rate to even 25 percent.

A corporate tax rate in the teens could be difficult to achieve if Republicans plan to pass tax-reform legislation through a procedure known as “reconciliation” in order to avoid a Democratic filibuster. Under reconciliation, legislation can’t increase the deficit outside of the budget window, so a tax bill either needs to be deficit-neutral or have at least some parts that are temporary.

Meadows said he would support extending the budget window from the traditional 10 years to 15 years in order to have tax cuts last for longer.

“In this city, 15 years is about as permanent as anything is,” he told reporters after the event.

Meadows expressed concerns about revenue-neutral tax reform that pays for tax cuts with tax increases elsewhere, but expressed an openness to deficit-neutral tax reform that includes spending cuts.

The Freedom Caucus chairman told conservative activists at the event to not accept excuses from Congress if tax reform moves slowly.

“If we do not have a bill that we’re actually debating in September, who hopefully gets a vote by October, it will not get to the president’s desk by Thanksgiving,” he said. “And if it doesn’t get to the president’s desk by Thanksgiving … it isn’t going to happen.”

Meadows said it’s important for tax legislation to be enacted this year so that it can be retroactive and apply to 2017.

If a tax bill doesn’t pass before January, the benefits of tax cuts will be delayed for a year, he said. Additionally, Congress is more reluctant to take tough votes in midterm election years.

“It’s a political reality in those midterm years, every thing starts to slow down and you do things around the edges,” Meadows said.

AFP’s event was the second this week that the Koch network held in Washington to promote tax reform. On Monday, AFP and Freedom Partners Chamber of Commerce held an event with Treasury Secretary Steven Mnuchin and White House Legislative Affairs Director Marc Short.

The Koch network in May launched a multimillion-dollar campaign to get lawmakers to back tax reform that follows five principles: simplicity, efficiency, equitability, predictability and no new burden on taxpayers.

AFP and Freedom Partners have run digital ads urging both Republicans and Democrats to support tax legislation that is in line with their vision.