There may be lines out the door at some New York courts over the next seven weeks, a Manhattan divorce lawyer predicts.

A New York law change that takes effect Jan. 23 will cut spousal support by as much as $9,200 a month, sparking the rush of spouses of well-to-do mates to splitsville, the lawyer, Jacqueline Newman, told The Post.

The law change will cut the cap on salary to be considered during computing spousal maintenance from its current $543,000 to $175,000.

A non-breadwinner married to someone who earns $500,000 could be awarded up to $13,575 a month in maintenance.

After Jan. 23, that amount will drop to $4,375, said Newman, of Berkman Bottger Newman & Rodd.

That’s a difference of $9,200 a month — or $110,000 a year.

Some non-breadwinner spouses had already secretly initiated divorce proceeding, the lawyer said.

“We already have a lot of clients starting actions now in what we call the pre-new maintenance law era,” said Newman. “These tend to be non-monied spouses who have 120 days to serve their other halves with actual divorce papers.”

The rush to divorce court could be particularly noticeable in Manhattan, one lawyer noted.

“The new law will not be good for a lot women,” said Harold Mayerson of Mayerson Abramowitz & Kahn.

He said those who could be hit the hardest are Manhattan moms between 45 and 55 who haven’t worked in years but have husbands making seven figures.

“I’d have my trial right now, if I were them,” Mayerson said. “Otherwise they could have real problems getting a fair maintenance.”

The law change will also shorten the period of time the non-breadwinner spouse can collect maintenance.

Currently, the guideline calls for someone married 10 years to collect for half the marriage’s life, or five years.

The new guidelines will shorten that to a maximum of three years.

The cumulative difference in what non-monied spouses who beat the deadline can gain from support payments exceeds $1 million — based on a 15-year marriage and monied spouses with an annual income of $750,000.