A last-ditch attempt is being made by US ports employers group United States Maritime Alliance (USMX) to avert a port workers strike that threatens to shut down the country’s ports at midnight eastern standard time on Monday.

USMX says it has submitted a new offer to the International Longshoremen’s Association (ILA) that it claims would increase wages by nearly 50%, triple employer contributions to employee retirement plans, strengthen health care options, and “retain the current language around automation and semi-automation”.