AUGUSTA – Gay marriage and expanded casino gambling are among the items that will be on the agenda when the Legislature returns to the State House this week to begin its final push toward a mid-June adjournment.

The Judiciary Committee has split along party lines over whether a state constitutional amendment to ban same-sex marriage should pass. In an incomplete tally, seven of the committee’s Democrats opposed the amendment, while five Republicans voted Friday to endorse it.

The divided vote sets the stage for debate when the proposal reaches the House and Senate in the days ahead. If legislative votes stay close to party lines, chances of the amendment passing would appear dim.

Passing a constitutional amendment requires a two-thirds supermajority vote in the Democratic-majority Legislature and then approval by voters.

Maine already has a law on the books banning same-sex marriage. But supporters of a constitutional amendment highlighting that statute say it’s needed to prevent the courts from forcing the state to legalize same-sex marriage, as the Massachusetts Supreme Court did two years ago.

Opponents of the amendment say the existing ban is sufficient because there are no court cases pending in the state to legalize same-sex marriage. Eighteen other states have amended their constitutions to ban same-sex marriage.

Another unresolved issue, whether to allow tribal casino gambling in eastern Maine, also faces dim prospects because Gov. John Baldacci has said he does not support it.

The proposal supported by the Passamaquoddy Indian Tribe would allow 1,500 slot machines in Washington County, within 45 miles of tribal land. Opponents say the bill could be construed to allow casinos almost anywhere in the state.

Penn National Gaming Inc. is completing the application process for a voter-approved racino in Bangor.

Baldacci, who indicated last week he was unlikely to sign the bill to allow expanded racino gambling, clarified his stand Monday. Asked if he would veto such a bill, Baldacci said he was “leaning in that direction.”

In the days leading up to a statutory June 15 adjournment of the session, the focus likely will turn toward financial matters. Lawmakers must complete work on a supplemental state budget, which involves reconsideration of a $450 million bond package that helps finance state programs.

Proposals to revamp taxes, including phasing out a business equipment tax, also remain on the table.