A spokesman for Pilgrims Retreat, owned by Sines Park Luxury Living, denied this and said residents knew what they were buying.
Pilgrims Retreat sells both residential and holiday properties.
The spokesman said: “In the event that a leisure park home is sold, the owner is made aware and given a copy of the 12-month leisure licence. This disputes all claims that leisure park homes are being mis-sold as residential park homes.”
Maidstone Borough Council is investigating, and has served planning contravention notices on all the Pilgrims Retreat homes and the owner.
Councils give these notices out to gather evidence when they suspect a breach of planning permission. Enforcement action can follow.
A spokesman for the council said: “The purpose of this is to gain a clear understanding as to who is occupying the site and on what basis.”
Gillian Keegan, the MP for Chichester, said she had also heard from her constituents about holiday homes being wrongly sold as permanent accommodation.
She said most are well-run sites but that “some of them are in the wrong hands, and bad practice can creep into leisure sites, creating an exploitative way of doing business”.
Councils have a responsibility to check that buyers of holiday homes have permanent homes and do not live in the holiday homes all year round.
However, this is often not enforced, meaning residents can buy properties in error.
But a spokesman for Maidstone council said the responsibility when buying holiday homes should fall on the buyer.
He said: “It is the responsibility of the buyers, via their solicitor, to fully understand the planning status of the park homes being offered for sale.”
However, unlike residential properties, many people do not use lawyers when buying holiday homes.
The MPs said they want to see greater oversight of estates to make sure consumers are protected and know what they are buying.
They also called for penalties for unscrupulous site owners and for these owners to be required to go through “fit and proper persons” tests.