The contract talks between the WGA and Hollywood’s major studios are expected to intensify on Friday as the guild delivers its formal response to the offers from the Alliance of Motion Picture and Television Producers.

The sides have held bargaining sessions during the past three days as the May 1 expiration of the current contract approaches. On Thursday, sources reported there was discussion of the WGA’s health plan needs and detail from the studio side on the proposal to adjust the compensation formula for writers working on short-order series and to more clearly define the time frame of a TV season.

Those issues, known by the shorthand of “span,” are among the most complicated aspects of the negotiations. A source reported there was discussion of the income thresholds that the AMPTP has proposed for writers to earn extra compensation for work periods that extend beyond 2.6 weeks per episode and to not be held off the job market by exclusivity clauses. AMPTP is believed to have proposed these changes for writers making less than $275,000-$300,000 per season.

One source on the studio side said there seemed to be movement toward compromise on the health plan and the size of the capital influx needed to keep it from racking up big deficits. However, that view of progress did not seem to be shared on the WGA side of the table.

The studios are most recently believed to have offered about $60 million over the three-year term of the contract while the guild is seeking closer to $85 million. There is expected to be more wrangling over the level of savings to be squeezed out through stricter management of the plan and its benefits in exchange for the lump-sum payment.

Negotiators on both sides expect the talks to go down to the wire on Monday. “Monday is going to be a real long day and long night,” said one source close to the situation.

In addition to health care and span, there are other outstanding issues such as the WGA’s bid for parity in script fees among broadcast, cable and SVOD outlets. It’s not clear whether the AMPTP will dig in to hold the line, but there is concern among the studios that big gains for the WGA in total would be demanded by SAG-AFTRA, which is up next for master contract negotiations on a deal that expires June 30.

On Friday, some of the studio members of the AMPTP are expected to send a memo to their staffers acknowledging the possibility of a strike if a deal is not reached by Monday’s midnight PT deadline. If no agreement is in place, the WGA West and East have vowed to initiate a work stoppage starting May 2 after securing overwhelming support from members in the strike authorization vote that concluded on April 24.