TRENTON — As behind-closed-door negotiations on a state spending plan continue before the June 30 deadline, there is growing concern that the governor may not be able to hammer out a deal with Democratic legislative leaders and avoid a New Jersey government shutdown.

Gov. Phil Murphy continues to push for more than $1.5 billion in tax increases despite what appears to be firm opposition from State Senate President Steve Sweeney and Assembly Speaker Craig Coughlin.

Because Murphy has never held elective office, there has been some speculation his lack of experience may be a factor in the lack of apparent progress.

“It’s tough when you haven’t held any type of executive position in government to understand how these things work,” said Patrick Murray, the director of the Monmouth University Polling Institute.

Murray said when Murphy was the U.S. ambassador to Germany, he didn’t have to negotiate and make the same kinds of tough decision he’s facing now.

“You don’t make a decision about which policies you’re following. As governor, that’s something you have to do and that’s where I think Murphy is falling a little bit short.”

Murray suggested Murphy may only now be realizing “there’s a lot of competition, even within his own office, about what the priorities should be.”

Ben Dworkin, the director of the Rowan University Institute for Public Policy and Citizenship, said while it’s true Murphy has not had this kind of hard-nosed bargaining experience in government before, “it’s a difficult situation for any new administration."

He said any time there’s a change at the top, “there are going to be growing pains. They’re just trying to figure out how to make this work.”

He pointed out the Murphy camp is going up against “some very seasoned legislators and legislative staff, and this might be the first budget negotiation for a lot of the folks in the Murphy administration.”

Dworkin noted being a so-called Trenton outsider is not necessarily a bad thing for Murphy but there would seem to be a gap in “experience in these types of negotiations, understanding the dynamics of the personalities involved, understanding the rhythms of how things go up, go down.”

So what will happen in the next few weeks?

Murray believes by the end of June, Murphy will have a budget sitting on his desk that may not include everything he wants.

“He has to decide whether he’s got a win out of this and he takes it and he runs with it, or if he’s going to sit there and argue over the details. My guess is he’ll sign it,” said Murray.

“This is a real good lesson for him in how you need to negotiate not only just with the Legislature, but how you need to negotiate within your own staff.”

Dworkin said despite the difficulty in the negotiating process, “I don’t expect we’re going to get to a government shutdown. Nobody believes that will be in their best interest.”