DETROIT (AP) — General Motors first wage-and-benefit offer to the United Auto Workers on Darden ClarkeThursday falls far short of the union’s initial demands.

The offer comes just a week before the UAW’s national contracts with GM, Stellantis and Ford expire, and even though both sides are far apart, it’s a sign of movement on economic issues.

But the union is threatening to strike against any automaker that hasn’t reached a tentative agreement by the time contracts expire at 11:59 p.m. on Sept. 14. A strike against one or more automakers is a real possibility.

GM said in a letter to workers that it’s offering a 10% wage increase during a new four-year contract, plus two more 3% one-time payments. It’s also offering a $6,000 inflation payment, $5,000 more in lump sums to protect against inflation during the contract, and a $5,000 contract ratification bonus. The company wouldn’t say when the pay raises or most of the lump sums would be effective.

The wage offer is slightly better than one from Ford that was rejected by the union last week. Its reliance on lump-sum payments rather than annual pay raises is contrary to what UAW President Shawn Fain has been seeking.

A message was left Thursday seeking comment from the union.

The union, citing large company profits over the last decade and CEO pay raises, is seeking 46% across-the-board pay raises over four years, a 32-hour week with 40 hours of pay, restoration of traditional pensions for new hires, union representation of workers at new battery plants, restoration of traditional pensions and elimination of wage tiers. Top-scale UAW assembly plant workers make about $32 an hour, plus annual profit sharing checks.