HELENA, Mont. (AP) — Republican-appointed commissioners are proposing their own plan for the new Montana legislative districts that could take shape this week.

The Montana Districting and Apportionment Commission started hashing out partisan differences Monday on proposed new House districts. The panel is charged with drawing new lines that adjust for population growth over the last decade. Members hope to make significant progress this week.

The day started with Republicans on the panel proposing a hybrid map that borrows from the four others already on the table. Democrats have an offering they prefer, and legislative staffers have drawn three alternatives. Commissioners spent Monday afternoon sorting out differences, but making little progress. Both sides will be vying for the tie-breaking vote of former Supreme Court justice Jim Regnier.