(WHITING) - A labor dispute is escalating at one of the Midwest's largest refineries.
According to CBS News, BP locked out union workers at its Whiting refinery starting last night after contract negotiations broke down.
The United Steelworkers union, which represents hundreds of employees, rejected the company's latest offer. The union claims the proposal includes job cuts and new surveillance measures.
BP says the refinery will continue operating during the lockout and does not expect any disruption to production.
Analysts warn any slowdown could impact gas prices, which have already been rising in recent weeks.