A Dorset woman has organised a protest in London to urge a change in the law to help people living in mobile homes.
Sonia McColl, from Wareham, and her supporters say they do not currently have enough legal protection from their park owner landlords.
They want a change in the Mobile Homes Act 1983 to stop park operators from preventing the sale of homes at the "approval of the buyer" stage.
Up to 100 people protested at Westminster on Wednesday.
Ms McColl said some "unscrupulous" park owners were preventing residents selling their homes in the hope of getting the properties themselves on the cheap.
She said: "I thought it was just where I was initially.
"I wasn't aware of it until I went into it and I found that it was at epidemic levels. There were so many people out there suffering and it's widespread."
The government has tried to offer assistance in the form of housing tribunals, but that has been rejected as "unworkable" by the campaigners.
Another campaigner, Margaret Kirkman, who chairs the Isle of Wight Residents Association, said many mobile home owners knew potential buyers would not wait for tribunals.
She added: "When they are contacted by the site owner and told that certain things have to be done, like the rent being increased, they simply just don't know that that isn't right."