A NJ Transit train arrives into a station in New Jersey. (Photo by Spencer Platt/Getty Images)

NEWARK, N.J. (CBSNewYork) — NJ TRANSIT may face a possible work stoppage if the railroad does not come to terms with two unions that still reject proposed contract negotiations.

NJ TRANSIT said if both parties do not come back to the table by Friday, they are going to start preparing for a shut down by mid-July.

NJ TRANSIT and labor unions representing its workers reached a tentative deal in March, averting the threat of a system-wide strike.

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The unions were seeking an 18.4 percent pay raise over a period of seven years, as well as pay retroactive to 2011. They also wanted health insurance costs capped at 2.5 percent of base pay.

NJ TRANSIT issued the $183 million estimate for that plan — for just the first two years. The agency has instead proposed a 10.9 percent raise over seven years, with employees contributing 20 percent of their base salaries toward health insurance.

In May, NJ TRANSIT spokeswoman Nancy Snyder told CBS2 that two of the unions involved in strike negotiations narrowly rejected the new proposed contract.

“NJ TRANSIT has been advised by the two unions representing its conductors and locomotive engineers that the membership has failed to ratify the recently negotiated agreements. Both ratifications failed by narrow margins,” Snyder said.

The union workers are demanding pay that is similar to that of their counterparts at the Long Island Rail Road, 1010 WINS Samantha Liebman reported.

One union has said they are already in negotiations.

As CBS2’s Meg Baker reported, the other unions will not cross the picket line, and it will be up to NJ TRANSIT to keep the trains running.

Federal officials have asked the two parties to continue a cooling off period until July 16, past the June 30 deadline.

NJ TRANSIT said it needs to know if it has a deal by tomorrow in order to put an operational plan into motion ahead of a possible strike or lockout on June 30.

Commuters are already expressing concerns over the possibility of a strike.

“If there’s a strike, it will be Armageddon,” one commuter said.

“A strike would not be ideal for commuters, but I understand where they’re coming from,” another commuter said.

With several unresolved issues like healthcare — a union rep said they remain at the table — they just need someone from management to sit across from them.

Neither side would go on camera.

NJ TRANSIT said 14 other unions ratified their contracts by significant margins, and for them the new contract is now in effect.

In 1983, NJ TRANSIT struck for a full month.

The other NJ TRANSIT unions said they won’t cross the picket lines. No one else can run the trains because it requires a certification with a special license.

NJ TRANSIT insists they have a plan and personnel to keep trains running next Thursday.

About 105,000 commuters rely on NJ TRANSIT daily.