Republican lawmakers are demanding that the Department of Labor turn over all documents relating to a proposed Occupational Safety and Health Administration rule that would make franchisers legally liable for violations at their franchisees.

The lawmakers accuse the department of planning to use OSHA to punish businesses for issues unrelated to workplace safety and hiding those efforts from Congress.

Senate Health Education Labor and Pensions Committee Chairman Lamar Alexander, R-Tenn., reminded Labor Secretary Tom Perez in a letter sent Tuesday that he asked the secretary directly at a March hearing whether OSHA was planning to adopt the same franchiser liability policy that the National Labor Relations Board, an independent federal agency that enforces labor laws, had advocated in a case against McDonald's Corp. last year.

"You were asked if OSHA was 'planning to follow the NLRB and hold franchisers jointly liable for labor law violations committed by franchises.' You responded, 'I am unaware of any OSHA action.' Yet, just five months later (a) leaked draft guidance shows OSHA has been working on a such a policy," Alexander said in a letter co-signed by Homeland Security and Government Affairs Committee Chairman Ron Johnson, R-Wis., and Sen. James Lankford, R-Okla.

The letter asks Perez when OSHA began drafting the policy and when he first learned of it. It also seeks all documents and communications at the department relating to the OSHA proposal and all communications betweeen department officials and NLRB officials, among other information.

A Labor Department spokeswoman did not have a response.

The NLRB's proposed joint employer policy has prompted outcries from business groups since it would vastly expand corporate legal liability. Critics argue the policy would force companies out of franchising or force them to assert more control over their franchisees to reduce potential liability, undermining one of the key enticements, local control, that make entrepreneurs want to open franchises. Business groups have pushed Congress to prevent the board from enacting the policy.

Alexander, Johnson and Lankford said the OSHA guidance would require its investigators to "ask for information that does not appear to be related to health and safety. For example, the guidance asks for information about franchiser fees, the creation of menus, the approval of signage, and whether suppliers are recommended, among many other things."

House lawmakers wrote to Perez expressing similar objections to the proposed policy earlier this month.

In a letter last month, Alexander asked the department whether OSHA and the labor board were working together on the joint employer policy.

"It looks like a coordinated effort to change the law to me," Alexander said.