Britain’s most controversial landlords, Fergus and Judith Wilson, whose property empire extends to nearly 1,000 homes in Kent, have begun evicting families with more than two children, banned tenants on zero-hours contracts and thrown out extended families where the grandmother comes to stay.

Last January, the Wilsons sparked a national outcry after it was revealed they were evicting anyone on housing benefit. They sent the eviction notices to 200 tenants, saying they preferred eastern European migrants who defaulted much less frequently than single mums on welfare. They said at the time that the move was purely an economic decision and was entirely legal as landlords do not have to give a reason before obtaining a possession order on a home.

But, in a bizarre twist, the Wilsons have begun evicting many of their eastern European tenants – because they are having too many children. “I have taken the decision to evict all families with more than two children and also three-generation households,” said Fergus Wilson in a statement sent to the Guardian.

“Most of our houses in Ashford go to childless couples. However, after a couple of months there are four, five, six children and I have to evict the family. The tenancy has been taken by deception. We have had a number of eastern European families slip in under the radar with four, five and six children. We have had no British tenants with three or more children for some weeks. They have been evicted as I took the decision to no longer take housing benefit cases. All those British tenants with three or more children have long gone.”

We asked Wilson how many families he has evicted on this basis. He said: “Eight to date, and at least four more to go.” He added that visiting grannies are also a problem. “Three-generation houses seem to be very popular with east European immigrants. When they move in the children, they move in grandma.”

Wilson claims that he has no choice but to evict multiple-occupancy tenants and large families because otherwise he would be in breach of council overcrowding rules. “Contrary to what may be depicted by the leftwing media, I do not eat little babies alive … I do not make the rules, but I do play by them … welcome to ethnic engineering at the coal face.”

But which rules on overcrowding Wilson is referring to are unclear. A property may be considered overcrowded if two children above 10 of the opposite sex have to share the same bedroom. But the Housing Act 1985 counts living rooms as well as bedrooms as available for sleeping, which makes statutory overcrowding in the private rented sector difficult to prove.

However, councils can also use health and safety rules to serve a legal notice on the property owner.

Like many other landlords across Britain, Wilson has also taken the decision to reject anybody who is on a zero hours contract. Around 1.4 million employees in Britain are now on zero hours contracts, with no guaranteed minimum hours or pay, and are facing mounting problems finding anywhere to live.

“I only have experience in rejecting them as tenants,” said Wilson. “No landlord in his right mind will accept tenants who do not have a guaranteed wage. No rent insurer will accept them, so that effectively makes the landlord’s decision for them. No pay … nowhere to live. Welcome to the real world.”

Earlier this year the Wilsons evicted Andrzej Koper and his daughter Anya after he complained about a non-working boiler – they claimed the timing was entirely incidental.

Rent guarantee insurance has become a product widely sold to buy-to-let landlords, and promises to pay out if a tenant defaults – usually with a cap of around £2,500 a month for six months – and may also cover legal costs for eviction. But before granting a rent guarantee, the insurer will require that the tenant goes through extensive credit referencing checks and income verification. In most cases it means that a person on a zero hours contract is declined for insurance and rejected as a tenant.

Given that the Wilsons are either evicting certain types of tenant, and rejecting other types of applicant, we asked just how many he had left. The reality, Wilson said, is that demand for property is so intense landlords can still pick and choose.

“I asked my agents to let me know how many calls were received from would-be tenants yesterday? Answer: 81. How many were from east European or overseas? 71. How many had children? 15. How many were on zero contacts? Nil. How many on housing benefit? Seven. How many houses available? Three.”

Campaigning organisations such as housing charity Shelter argue that the balance of power has swung too far in favour of landlords, against tenants who are chasing a limited supply of property and can be evicted without reason.

Roger Harding, Shelter’s director of communications, policy and campaigns, said: “It beggars belief that a landlord can evict a family simply because they have three children, and the fact that this one has is yet another sign of our broken rental market.

“For many families, private renting is their only option. Families now make up nearly a third of private renters and if more landlords turn them away this will make it near impossible for many to find anywhere half-decent to live. Politicians must make private rented homes a stable place to put down roots, and not somewhere you can be turned away from for no good reason.”

Behind the Wilsons’ recent actions lies another motive; preparing their portfolio of homes for a trade sale. In July, they said they planned to withdraw from the property business, selling their entire portfolio of nearly 1,000 homes in the Ashford and Maidstone area in a deal likely to net them at least £100m. “I have had three firm offers for our property portfolio, and while I am considering these I have to manage the portfolio on a day-to-day basis.” The Wilson are understood to have been in negotiation with investors from Dubai and the far east.

The couple first shot to prominence in 2006 when it was revealed that they had built up Britain’s biggest buy-to-let empire, sometimes snapping up a property every day.

Fergus Wilson said a bounceback in the local property market to above 2007 levels has prompted him to quit. In an email to the Guardian in July, he said: “We are selling up the whole lot! The market has recovered and passed the 2007 level. I would like it to end up in English hands, but it is a case of who will pay top dollar!”