Maryland Gov. Larry Hogan (R) on Monday vetoed a bill that would put a nonpartisan commission in charge of drawing the state’s congressional districts if five other states agreed to do the same.

His rejection of the measure immediately sparked criticism from Democratic leaders and potentially sets up a veto-override vote next year in the state legislature, where Democrats have strong majorities in both chambers.

Hogan described the vetoed bill, sponsored by Sen. Craig J. Zucker (D-Montgomery), as a “phony bill masquerading as redistricting reform.” He noted that the measure failed to address redistricting of Maryland’s legislative districts and said the chances of a multistate compact for congressional maps are unrealistic in today’s political climate.

He said he preferred a single-state solution, which he has proposed for the past two years.

The Maryland chapters of Common Cause Maryland and the League of Women Voters, which have pushed for a nonpartisan redistricting process to end partisan gerrymandering, applauded the governor’s veto, saying in a statement that the proposal for a multistate compact “set an impossibly high bar.”

House Speaker Michael E. Busch (D-Anne Arundel) and Senate President Thomas V. Mike Miller Jr. (D-Calvert) issued a joint statement criticizing the governor’s veto.

“Today’s veto reveals that, instead of supporting a true, non-partisan solution that could restore accountability and cooperation to Washington, Governor Hogan prefers his plan to simply elect more Republicans to Congress,” the leaders said.

They did not comment on whether they will try to overturn the veto, which requires 85 votes in the House and 29 in the Senate.

The bill received 30 votes in the Senate and 87 in the House.

Hogan has proposed that Maryland act alone in creating an independent redistricting commission to draw the state’s congressional and legislative districts. The measures died in committee both years.

Maryland Democrats have said the state should not unilaterally switch to independent redistricting while many Republican-dominated states continue to gerrymander their voting maps.

Bryan Lesswing, a spokesman for the state Democratic Party, said Hogan’s redistricting plan would hand President Trump and congressional Republicans “more votes to carry out their agenda.”

The state Republican Party is working to end the veto-proof Democratic majority in the Senate by taking over five seats in the 2018 election, a change that could force Democrats to compromise with Hogan more on legislation.

Sen. James Brochin (D-Baltimore County), who stood with Hogan at the veto news conference, said he supports the governor’s proposal.

He said his party is “missing out on the boat, and they may end up being very sorry in the next election if they hold their ground.”