Asylum-seekers have been placed in rat-infested and dirty accommodation after arriving in the UK, a Commons report has warned.
MPs delivered a blistering critique of the system for housing those who apply for refuge in Britain, describing some of the conditions in properties as a "disgrace".
The Home Affairs committee heard evidence of families living amid infestations of mice, rats and bedbugs.
One woman complained that her kitchen was "full of mice", saying "they even ran across the dining table while we were eating".
Providers were accused of failing to ensure items they are obliged to provide are present and in working order when a person is placed in accommodation.
Since 2012 accommodation has been provided to asylum seekers via six regional contracts, which are delivered by three providers - Serco, G4S and Clearsprings Ready Homes.
The report said the poor standard of accommodation was the most significant issue identified in the evidence it received, which focused largely on contracts administered by G4S and Serco.
Labour MP Yvette Cooper, the committee's chairwoman, said: "The state of accommodation for some asylum seekers and refugees in this country is a disgrace.
"We have come across too many examples of vulnerable people in unsafe accommodation, for example children living with infestations of mice, rats or bed bugs, lack of healthcare for pregnant women, or inadequate support for victims of rape and torture."
The "dispersal" scheme used to place asylum seekers around the country is not working, the committee concluded.
It found applicants are concentrated in a small number of some of the most deprived areas - placing pressure on local schools and healthcare services.
A large number of local authorities are not taking part in the voluntary scheme.
MPs called for measures to increase participation but said if town halls continue to fail to sign up, then the Government should use powers to compel them.
Ms Cooper said: "It is completely unfair on those local authorities and communities that have signed up and are now taking many more people, when so many local authorities in more affluent areas are still doing nothing at all."
Contractors are housing more people than they were funded for because of the contract design, growing delays in Home Office asylum processing and higher applications, the committee added.
A Home Office spokeswoman said: "We work closely with our contractors to ensure they provide accommodation that is safe, habitable, fit for purpose and adequately equipped and we conduct regular inspections to check that this is the case.
"We have also made significant improvements to the operation of the contracts including increasing the number of dispersal areas by more than a third."
David Simmonds, chairman of the Local Government Association's asylum, migration and refugee task group, said: "Councils are stepping up to the plate, with more than 200 local authorities becoming dispersal areas.
"We hope that the Government's future contracts for asylum accommodation and support addresses the challenges in securing accommodation in other local authority areas, particularly where there is limited availability and high-cost housing."
John Whitwam, G4S head of immigration and borders, said the report "sets out the challenge of housing double the number of asylum seekers than were forecast under this contract while three-quarters of local authorities in the regions in which we work do not allow us to place people into their areas".
He said: "The standard of accommodation provided to asylum seekers is an important measure of the UK's commitment to give sanctuary to those fleeing persecution abroad.
"The report makes clear that these standards have generally improved over the past two years, and whilst the isolated examples of poor practice raised are clearly unacceptable, we do not believe they are a reliable guide to the standards the overwhelming majority of asylum seekers coming to Britain can expect to receive."
Mr Whitwam added: "The standard of accommodation provided to asylum seekers is subject to prescriptive criteria, and any failure to meet these results in a contract penalty.
"Since November 2013, we have not been subject to any performance penalties on the basis that we rectify many tens of thousands of defects each year to meet the required standard."