A group that backs the tax overhaul and President Donald Trump’s agenda push in Washington is urging Rep. Dan Donovan to back the legislation.

Donovan, a Staten Island representative, is among the Republicans from New York who voted against the House version of the tax reform bill in November. At the time, Donovan pointed to the measure ending the deduction of state and local taxes. The Senate version of the bill does the same.

The ad released on Thursday pushing Donovan is from the 45Committee, a conservative 501(c)(4) group that conducted a media campaign in support of Trump’s cabinet nominations, including Tom Price and Jeff Sessions at Health and Human Services and at the Department of Justice.

“We elected Donovan to cut taxes, so ask him if he won’t keep his word to support tax reform, how can we ever trust him again?” the ad’s narrator says.

Donovan is facing a potential primary challenge from former Rep. Michael Grimm, a Republican who was convicted of tax evasion and is backed by former Trump political advisor Steve Bannon.