Gov. Phil Murphy is warning the Legislature that there will be political consequences if his millionaire's tax is not included in this year's budget.

Leaders of some of the state's most powerful unions joined the governor in Trenton Tuesday to issue a challenge to the Legislature.

"We will be at your office tomorrow," said Ray Greaves, Amalgamated Transit Union State chair. "We will be on the phones each and every day urging you to do the right thing, to be on the side of the people of the state of New Jersey and not in the pockets of a few millionaires."

At the State House, legislators were advancing a budget that doesn't include a millionaire's tax. It could set up a showdown with the governor when the fiscal year ends on June 30.

If the Legislature passes a budget, the governor can veto it or refuse to sign. If there's no spending plan in place by midnight June 30, state government will shut down.

A vote on the legislature's budget is scheduled for Thursday.