President Donald Trump and his allies are laying the groundwork to intervene in the November 3 midterm elections by raising claims about foreign meddling, according to the Democratic leaders of the House and Senate intelligence committees.

Representative Jim Himes and Senator Mark Warner say the administration is hiding less alarming current intelligence while making claims about the electoral system’s vulnerability to foreign interference, including by China.

They fear the administration could use claims of interference to seize ballots in closely contested races, or even impound voting machines before polls close. Warner said he has lined up prominent former election security, intelligence, law enforcement and military officials to push back on any such efforts.

“This is not just a legitimate concern; it’s a probable scenario,” Himes said in an interview. He warned of a false Election Day claim that could disrupt voting in a key state.

The claims come as early voting begins in several states. Election experts say the use of federal power around elections in this manner would be unprecedented.