In a letter to members, UAW leaders said Friday evening the union presented General Motors a new proposal as a nationwide strike passed 26 days.

If GM agrees and accepts the union's counterproposals, "we will have a tentative agreement," said Terry Dittes, the UAW's vice president of General Motors Department.

The counterproposal included, "all your outstanding proposals that are all at the main table and unsettled," the letter said.

GM said it had no immediate response.

UAW made the counteroffer after a day of sharp exchanges with GM.

The union said bargainers would continue to work over the weekend to reach a tentative agreement. GM on Thursday evening had urged round-the-clock bargaining.

In what became a public war of words late Thursday, the UAW said Friday that GM is "playing games," a day after the automaker complained that the union is going too slowly in talks to end its 26-day strike.

In a strongly worded statement earlier in the day, the UAW said the company has not taken the union's demands seriously at the expense of workers.

The two sides did hold their first "main table" talks in four days, people close to the negotiations said, but the union still had not presented the company with a counterproposal to GM's Monday offer. Subcommittees continued talking through the day.

In a video sent to union members, the UAW's lead negotiator, Dittes, said wages and a pathway for temporary workers to become permanent employees were not yet secured. He said the union is working around the clock to get a good agreement and urged members to last "one day longer in solidarity."

Friday morning, GM told all its hourly and salaried employees that it is "critical" the strike against the company end and a tentative contract agreement is reached.

The letter, written by Gerald Johnson, GM's executive vice president of manufacturing, said the automaker’s most recent proposal would offer wage increases, boost profit sharing, leave health care benefits intact with no cost hike, provide a pathway to permanency for temporary employees and ensure investments in U.S. manufacturing.

Johnson wrote: "We have advised the union that it’s critical that we get back to producing quality vehicles for our customers. We are committed to the collective bargaining process, and we are committed to our future together."

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Some 46,000 GM autoworkers represented by the UAW have been on strike since Sept. 16, after their 2015 contract expired two days before that.

Friday's letters followed another exchange Thursday from the top negotiators on the two sides that indicated tensions over the pace of negotiations. The union on Thursday said it would give the company "a comprehensive proposal" after subcommittees have completed renewed work on outstanding issues. GM's response urged them to speed it up.

In Friday's note to GM employees, Johnson said the strike has created hardships for everyone tied to GM, including the community, suppliers and car dealers.

He wrote: "From the outset, General Motors has been committed to an agreement that is fair and worthy of our team members’ support. That’s why before the contract deadline, we made an offer that we felt was strong. And since that offer, we’ve done even more to address the issues the UAW has brought forward."

Johnson said GM presented another offer on Monday that it believed met both sides' objectives.

He wrote: "It would increase compensation through wages and lump sum payments, preserve industry-leading health care benefits without increasing out-of-pocket costs, enhance profit-sharing with unlimited upside, and improve the ratification bonus. For temporary workers, our offer also would create a clear path to permanent employment and include a ratification bonus.

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"Our offer commits to thousands of new jobs right here in the U.S. and billions of dollars in new investments in our communities."

UAW strikers dig in

But the UAW issued a public response around noon. It said the members stand behind their negotiators and continue to hold out for a good contract. The statement also criticized GM's handling of negotiations.

"At every step of the way, GM has attempted to undermine the ongoing, good-faith efforts the UAW has made to end this strike," said Brian Rothenberg, UAW spokesman in a statement to the media.

"The company’s strategy from day one has been to play games at the expense of the workers," said Rothenberg. "It has released half-truths, ripped away health care in the middle of the night and it reverted to previously weak and unacceptable proposals in response to the UAW’s comprehensive solutions."

UAW members want to return to work, but, "GM is purposefully stalling the process to starve UAW-GM workers off the picket lines to protect millions of dollars of corporate bonuses. This strike has been and continues to be about securing the American workers’ future."

Dittes video statement:

The union said its negotiators continue to stay at the table "night and day to get a good deal for our workers and to end this strike."

The statement included quotes from union members showing support for UAW leadership and contract demands.

“We’re all out here doing our duty,” says Brian Kennedy, a spokesman for UAW Local 431. “We’re in support of our leadership; we know that they’re going to do the right thing."

Separately on Friday, union strikers marked the day with two rallies at GM's Tech Center in Warren.

Stuck in subcommittees

In letters exchanged between the union and GM top negotiators late Thursday, a tentative agreement did not appear to be coming soon.

Dittes said in the letter to GM labor Vice President Scott Sandefur that after that work is done, the union will answer GM's offer that it presented Monday.

Dittes wrote: "The completion of those committees is not known at this point, but they have been meeting since our 3:30 p.m. meeting" on Wednesday."

Sandefur replied in a letter that GM had expected the union's proposal on Thursday.

"Yesterday, you indicated the union would refuse to meet or give any response to the company's comprehensive offer unless each of the five areas referenced in your letter were resolved on a single-issue basis. We object to having bargaining placed on hold pending a resolution of these five areas."

Among the topics subcommittees are discussing are future products, sourcing, rules about idling plants during the life of the contract and the fate of the GM-UAW Center for Human Resources, which has been caught up in a federal corruption investigation that has led to 11 people being charged.

Sandefur added, "As we have urged repeatedly, we should engage in bargaining over all issues around the clock to get an agreement. Your members and our employees' lives are being disrupted, and they deserve our commitment to getting any remaining issues resolved as quickly as possible."

A UAW spokesman referred to Dittes' letter Thursday evening in response to Johnson's letter.

The letters both referenced a meeting Wednesday involving GM CEO Mary Barra and union leaders. People familiar with the talks said that meeting had given new life to the negotiations, which had appeared to have bogged down over company commitments to future U.S. production.

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Unusual talks

It is customary, when a deal is near, for the CEO and the leader of union’s negotiations to meet, said Harley Shaiken, a professor at the University of California Berkeley. He specializes in labor and has followed these negotiations closely.

"That is when there is the final set of trade-offs to remove the roadblocks," Shaiken said. "What is unusual here is it appears there are significantly bigger differences here with how either side is looking at it and that’s why they had the meeting.”

The public discourse volleying back and forth between GM and the UAW in letters to their constituencies at this stage in the bargaining is unprecedented and rare, said Shaiken.

“This was the time when Walter Reuther would bring his toothbrush and everybody was locked in for the end game,” said Shaiken, referring to the legendary UAW leader. “This is indicating that GM, which everyone thought could weather the storm, is anxious to sign the deal.”

The public discourse is also not constructive, Shaiken said.

“There’s a reason bargaining is private — you need flexibility at the table,” Shaiken said. “The actual trading is explored with a smaller group at that table.”

It appears that GM is worried about financial losses as well as lost sales that might not be recouped after the strike, Shaiken said. But the UAW is not about to rush into a deal it fears membership will reject. The disconnect between the two sides is likely because GM’s offer is “not the glowing report that GM is laying out” in its letter to employees, he said.

“GM has somehow missed the link that is at the top of the list for so many workers: The Monday after Thanksgiving you announced four plants would close. GM has said, ‘We have found jobs for almost all the workers that have been displaced and somehow the disruption to the families and communities are not in the picture let alone the impact on suppliers in those areas,’ ” said Shaiken. “Workers are looking at a profoundly different reality on the ground.”

The union was angered in November when GM said it would not assign new vehicles to two U.S. assembly plants, Lordstown in Ohio and Detroit-Hamtramck, and no future work for transmission plants in Warren and Baltimore. Lordstown and the transmission plants are idled; Detroit-Hamtramck is to operate at a reduced level until January.

But the two sides do have one thing in common, he said: They both want GM to be a competitive and profitable company.

“But for these workers who’ve been out almost a month, they have a huge investment in getting it right and if they don’t do it now, there may not be that opportunity in four years,” said Shaiken.

GM's motivation to try to push for a resolution could be rooted in Wall Street concerns.

The UAW strike may force credit raters to move the company closer to junk status, according to Bloomberg Intelligence.

The strike has passed the two-week threshold that raters, including Moody’s Investors Service and S&P Global Ratings, had said posed downside risk.

In an Oct. 9 report, Bloomberg Intelligence analyst Joel Levington wrote that the “fuse is burning” for ratings that, in Moody’s case, are just one notch above junk.

Last week, Moody’s said it was considering downgrading GM bonds to junk status. That rattled some because it means "GM would have to pay higher interest on borrowing, and that is a real cost to continuing this strike," Shaiken said in a previous Free Press interview.

Contact Jamie L. LaReau: 313-222-2149 or jlareau@freepress.com. Follow her on Twitter @jlareauan. Read more on General Motors and sign up for our autos newsletter.