Here’s one reason the proposed 7 train extension to New Jersey likely won’t happen anytime soon: The federal government doesn’t trust the Garden State.

After New Jersey Gov. Chris Christie abruptly killed the ARC tunnel under the Hudson River in October, the canceled project suddenly freed up $3 billion for the Federal Transit Administration to dole out.

But don’t expect them to hand that cash right back over for a subway line that would greatly benefit New Jersey. “The FTA is ticked off,” said one transit expert. “They bet the farm on ARC and then New Jersey pulled the plug. It was an embarrassment.”

“The federal government surely must be concerned about getting burned again,” said another source close to the plan. “Does New Jersey get a second chance?”

Federal funding is essential to the project, said Jeff Zupan, a senior fellow at the Regional Plan Association.