Peabody said Friday Big Ridge had filed objections with the National Labor Relations Board and was seeking a new election based on “numerous” reports of intimidation and threats, coercion and fraudulent conduct that affected the recent UMWA election at the operation.

A vote on May 19 and 20, conducted by the NLRB, was close with 219 to 206 workers voting in favor of UMWA representation. The union is seeking to replace former representative the International Brotherhood of Boilermakers.

“The filing states that during the election campaign union advocates threatened employees and their families with bodily harm, contributing to an atmosphere of coercion that interfered with employees' free choice,” the company said.

Big Ridge also alleged the union distributed false and fabricated documents during the campaign.

“All of these acts contributed to fear and confusion that prevented employees from exercising their rights to choose and speak for themselves regarding their working conditions.”

Peabody said employees had a right to choose whether or not to be represented by a union.

“Incumbent in that choice is the right to a free and fair election, unfettered by intimidation, fear and misinformation. The workforce at Willow Lake was not afforded that opportunity,” the company said.

Last week the UMWA announced the addition of the 444-worker Willow Lake operation to its representation fold.

Union president Cecil Roberts said the workforce sought the group out in a “struggle to gain a strong voice at work”

“We look forward to sitting down with the company to negotiate a fair and equitable collective bargaining agreement as soon as possible."

The underground mine in Equality, Illinois, has more than 20 million tons of recoverable coal reserves. It began shipping coal in 2002 and sold 3.5Mt in 2009.

The UMWA represents more than 105,000 active and retired coal miners as well as manufacturing workers, public service employees, health care workers and professional employees in the US and Canada.