A cross-party delegation of three Conservative and three Labour MPs hopes to convince culture minister Ed Vaizey that government funding for the National Coal Mining Museum for England, in Wakefield, should not be cut.

Kevin Barron, Labour MP for Rother Valley, said he would make the case for the “unique nature of the museum” in a meeting this month with the minister.

“The museum is classified as a working coal mine and, according to statutory regulations, a certain number of people need to be employed there,” he said. “A cut across the board could cause lasting damage.”

Museum director Margaret Faull said: “Running costs are closely linked to the number of visitors. Every group going underground requires the input of four guides. Our grant-in-aid covers the cost of taking only 100,000 visitors underground, but we have about 120,000 people.”

With funding cuts of up to 30% expected in the October spending review, Faull is considering closing the museum one day a week.

“In the meantime, we have frozen recruitment for the posts of commercial director, marketing manager and conservator,” she said.

Faull denied local press reports which stated that the museum may introduce admission charges, pointing out that a suggestion made in 2002 to a Department for Culture, Media and Sport (DCMS) minister about charging visitors for the underground tour was rejected.

The museum is funded by the DCMS through the National Museum of Science & Industry (NMSI). It received £2.8m grant-in-aid for 2010-11, while its running costs are £3.3m.

The issue of charging was also addressed by a spokeswoman at another NMSI museum, the National Railway Museum in York. “Our [DCMS] operating grant is dependent on our continuing to offer free entry,” she said.

“We hope, however, that we can encourage visitors to make donations, in the knowledge that any help goes straight to improving the experience we offer.”