A Republican-aligned group is funding a new multi-million dollar advertising campaign to build support for the $1.5 trillion tax plan that's nearing final approval in Congress. 

The American Action Network launched a $2 million campaign targeting 24 congressional districts represented by Republicans. The list of targets includes three in New York: U.S. Rep. Claudia Tenney (NY-22), U.S. Rep. John Katko (NY-24) and U.S. Rep. Chris Collins (NY-27). 

"Our outdated tax system has been a burden on hardworking Americans for far too long," said Corry Bliss, executive director of the American Action Network. "Luckily, those days are nearing an end." 

Republicans tout the tax plan as a boon for the middle class. They claim it will save the average family $1,200. They also highlight other provisions in the legislation, including reducing the corporate tax rate from 35 to 20 percent and consolidating income tax brackets. 

But critics say it will only benefit rich corporations and high income earners while increasing the national debt by $1.5 trillion. A Quinnipiac University poll released this week found 53 percent of American voters oppose the GOP tax plan. 

The American Action Network has been a leading proponent of tax reform for months. The group has spent at least $24 million encouraging Republicans to support an overhaul of the tax code. The investments have targeted several GOP members in New York, including Katko and Tenney. 

The House and Senate have passed separate tax proposals. A joint conference committee has been formed to negotiate a final agreement. Congressional leaders hope to finalize the bill by the end of the year.