More than 175 years after the Tolpuddle Martyrs were transported to Australia, a bitter dispute over workers' rights has broken out at the courtroom where the six men were sentenced.

A group of blue badge guides is refusing to show visitors around the old crown court in Dorchester because of a row over their pay.

Some of them are furious that their action is being undermined by a colleague who has vowed to continue to show people around the courtroom where Judge John Williams dealt so harshly with the Tolpuddle trade unionists.

One of the guides refusing to work, Alistair Chisholm, said: "We are not a radical bunch. We are loth to take direct action, but what they are offering is well below the value for that which we offer."

Chisholm said he was angry that another guide, Christine McGee, was prepared to go on working. "The story of the Tolpuddle Martyrs is all about solidarity and sticking together to get a fair day's pay for a fair day's work," he said. "We have pointed out to Christine that she is undermining our protest."

Another guide, Derek Pride, a 69-year-old retired civil servant, said he was disappointed not to be showing people around the courtroom this summer. "I enjoy doing it," he said. "But it is a point of principle over the money."

McGee, however, said she was happy to continue to show people around the court. She said: "I find this extremely boring. It is up to the other guides to decide what they want to do. We are all individuals."

A spokesman for West Dorset district council, which allows free access to the courtroom, said it had already boosted the guides' pay this year. The spokesman said: "The guides work in two-hour sessions on summer afternoons. Last year, they were paid £26.65 plus travelling expenses for this and conducted three tours of the building. At the request of some of the guides, we have increased this fee to £30 for this summer and reduced the number of tours required to two."

The tours of the court will take place from 2 August to 31 August, Monday to Friday. The spokesman said the court would usually be opened "a bit longer than this".