General Motors and the United Auto Workers tentatively reached an agreement on Tuesday to give temporary workers a clear path to becoming full-time employees, helping pave the way to ending a strike that has gone on for 30 days, The Post has learned.

GM will give all temporary workers — who make between $15 and $19 an hour and have fewer benefits — the opportunity to become full-time workers after three years of consecutive service, according to a source familiar with the negotiations.

Temporary workers not only make far less than full-time workers, they have no access to retirement benefits, fewer days in paid time off, and a less robust health care plan, the person said.

The change will also apply retroactively to all workers who have already worked on a temporary basis for more than three years, according to the source.

In all, the change will affect 4,000 UAW workers at GM across the country, the person said.

While the details are still being hammered out by negotiators, the company and union representatives have reached an agreement in principle, the person said.

The breakthrough comes as negotiations are starting to turn a corner, and a full agreement could come as soon as tonight or tomorrow, the source said.

A GM spokesman declined to comment.

Mary Barra, GM’s CEO, met with UAW negotiators for a second time on Tuesday morning to encourage the end of the strike.

As first reported by The Post, Barra met last week with UAW’s leadership for the first time at a period when negotiations were stalled and tensions were running high.

While UAW brass has discussed holding a “no confidence” vote in Barra in order to bring her to the table, that was later described to The Post as “the nuclear option and the absolute last resort,” according to the source.

The two sides are still negotiating around other issues, like bringing up the manufacturing of entire auto lines from Mexico to the US.