Drug dealers in Swansea risk losing their homes if they are caught selling drugs from council houses.
The warning from Swansea Council comes after 27 people were found guilty of supplying Class A drugs.
All those convicted, who were jailed following Operation Avignon, may also be evicted from their homes.
But Swansea-based charity Cyrenians say the plans would place homelessness charities "under increased pressure".
Swansea Council issued its eviction warning to council tenants, which includes those who allow people living with them or visiting their home to use the property for drug dealing.
'Free from the misery'
Lee Morgan, Swansea Council's head of housing and community regeneration, said the council considered drug dealing to be a "serious breach of tenancy conditions" and if an offence was proved, eviction was the likely end result.
"Drug dealing is a serious crime that has many victims including drug users, neighbours and the wider community," he said.
"The impact of drug dealing on communities can be immense with problems such as anti-social behaviour, theft and violence often a direct consequence."
But the council stresses help is also at hand for people who need it.
Mrs Morgan added: "We do offer support through our tenancy support unit or other specialist agencies to any residents who find themselves vulnerable as a result of their substance misuse.
"By taking a variety of proportionate actions and working in partnership with other agencies such as the police and the voluntary sector, we're determined to ensure that all Swansea Council tenants enjoy a decent quality of life, free from the misery that drug dealing and using can bring."
Cyrenians director Conrad Watkins said: "It's important to treat evictions on an individual case-by-case basis, rather than apply a catch-all policy. And of course there are often innocent spouses and children to consider.
"If local authorities are taking action of this kind through widespread evictions, it is going to place charities and third sector organisations under increased pressure, when they are already under strain from the effects of the recession.
"Front-line organisations will need considerably more resources to deal with the effects of this policy.
"Swansea does not, as things stand, have sufficient emergency accommodation to meet the numbers of homeless people that are currently in the city. Expect to see the homeless figures rise."