Negotiations for a new WGA film and TV contract will resume this afternoon in advance of tomorrow night’s strike deadline. The rare Sunday bargaining session is a sign that the two sides are “moving closer to a deal,” a knowledgable source told Deadline.

On Saturday, the source said, management’s AMPTP made “big movement” on one of the WGA’s main demands – a new pay formula for writers and writer-producers employed on short-order TV series.

Bringing pay for New Media shows up to parity with network shows and rescuing the WGA’s ailing health plan are among the other key issues.

The guilds’ current contract expires Monday night at midnight, and members of the WGA East and West have voted overwhelmingly to authorize a strike if the talks fail to produce a fair deal.