Attorney General Martha Coakley is calling on National Grid to fix payroll system glitches that have caused nearly 2,000 Massachusetts workers who performed power restorations and other work after Hurricane Sandy to be paid improperly.

Coakley’s office, which enforces state wage and hour laws, sent a letter to National Grid Friday, directing the company to “rectify all Massachusetts unpaid wage issues by no later than December 21” or be penalized.