House Democratic candidates in town this week for training at the Democratic Congressional Campaign Committee in Washington got a visit from AFL-CIO President Richard L. Trumka for some tips on how they can win back working-class voters.

“I don’t have to tell you that you can’t count on the D next to your name to gain our support,” Trumka told Democratic leadership and a room full of candidates on Red to Blue, the DCCC’s program for its strongest candidates.

This is the first time the labor leader has spoken to DCCC candidates this cycle, though he has done so in previous cycle. He told the congressional hopefuls that the AFL-CIO is prepared to lend them its support, if they embrace the group’s agenda. Democrats need a net gain of 23 seats to win the House majority in November.

“We are ready to move heaven and earth to help a genuine ally,” Trumka said, citing organized labor’s early involvement for Pennsylvania Rep. Conor Lamb in his upset victory in a March special election in a district that President Donald Trump carried by 20 points in 2016.

The AFL-CIO is prioritizing “member to member” contact this cycle to ensure their members get out to vote.