Gov. Phil Murphy can't promise he won't ask for a second round of tax increases if the New Jersey Legislature goes along with the first, but he sure as "heck" would prefer not to, he said Monday.

The freshman governor, whose political mettle is being tested as his administration tries to get more than $1.5 billion in new taxes passed by the Legislature before July, told Star-Ledger editorial page editor Tom Moran that he has to leave the door open for additional tax hikes further on.

"You have to. But believe me, it's the last move I'll want to reach for at that point," Murphy said during an on-camera interview in Newark.

The Democratic governor is getting forceful pushback against his tax proposals from the Legislature, whose Democratic leaders would rather talk about structural reforms and spending cuts.

Murphy said he understands why new tax hikes would be of particular concern to members of the state Assembly, who face re-election in 2019.

"You'd like heck not to (raise taxes again)," Murphy said. "You don't want them to think -- and I don't blame them -- and more importantly you don't want the 9 million residents to think this is the first chapter in what's going to be an 'oh boy here we go again'," he said.

Murphy is proposing to boost funding for NJ Transit and public schools through increased taxes on millionaires and raising the sales tax back up to 7 percent. His budget also calls for additional pre-K funding and money toward tuition-free community college. He's said that investing in an educated workforce and quality education should pay off in economic expansion.

New Jersey lags the U.S. in economic growth, and Murphy said he's optimistic that an uptick in the rate of growth will shake out enough cash to "cover the future installments" of those spending proposals.

"I view this as a major reset," Murphy said. "The middle class has been somewhere between ravaged and ignored. I want to reset this in one boom."

Samantha Marcus may be reached at smarcus@njadvancemedia.com. Follow her on Twitter @samanthamarcus. Find NJ.com Politics on Facebook.