Town hall chiefs have urged magistrates to use new powers to impose much bigger fines on rogue landlords - warning the present "paltry" punishments are a drop in the ocean compared to the income they get from exploiting tenants.
The Local Government Association (LGA) said its efforts to bring to book individuals who housed people in "hell hole conditions" were being frustrated by an overly-complicated legal process that often left local taxpayers out of pocket.
It has compiled a catalogue of cases where the owners of "filthy and dangerous" properties had got away with no more than a "slap on the wrist" that would not act as a future deterrent to protect tenants from their abuses.
The Government announced this week that it was legislating for a fourfold increase in the maximum fines available to magistrates - and to allow them in future to impose unlimited fines in cases, such as many landlord offences, where the previous maximum was £5,000.
According to the LGA, o ne landlord received a fine of £100 in a case where six tenants were left living in a "hovel" for a year with no fire alarms and proper escape routes and it said the punishments being issued were "inconsistent".
Mike Jones, who chairs its environment and housing board, said: "The current system for prosecuting rogue landlords is not fit for the 21st century.
"Criminal landlords are exploiting this and endangering tenants' lives. They are treating the paltry fines as 'operating costs', which they are offsetting against the vast profits they are raking in.
"We need a system which protects the good landlords, whose reputation is being dragged down by the bad ones.
"We are talking about properties with fire escape doors opening out onto three storey drops and without proper front doors so tenants have discovered strangers dossing down on their sofas.
"Rogue landlords are calculating they can keep these going while the cash tumbles in and walk away after a year with a slap on the wrist.
"Councils are doing everything they can to tackle the rising levels of rogue landlords caused by the housing crisis. However, they are being hamstrung by a system racked by delays, bureaucracy and feeble fines.
"We need a new streamlined system which is much fairer, faster, more efficient and treats the criminal abuse of tenants seriously. Prosecution in its current state simply is not seen as an effective deterrent by rogue operators."
He said the majority of landlords were reputable, but there was a " growing minority of criminal operators".
"In many cases, councils are actually being left out of pocket because they are not even recovering the costs of bringing the prosecutions.
"It is imperative this changes because, at a time of unprecedented austerity, ultimately the taxpayer foots the bill. Meanwhile, some of the rogue operators who face feeble fines are getting away virtually scot-free. This is utterly unacceptable."
In Wolverhampton, the c ity council evacuated tenants from one house which had no electricity, gas, water or fire alarm, a missing fire escape which meant doors opened straight onto an outside drop of three stories and no locks on the doors, resulting in tenants finding a stranger asleep on their sofa.
The landlord was fined just £2,600 and the council was left out of pocket by almost £5,500, the LGA said.
Another, in Redbridge, who failed to deal with a mouse and cockroach infestation in a house where 10 people - including two children, shared a damp and mouldy kitchen, was fined £3,000, it added.
Housing Minister Kris Hopkins said: "We are determined to tackle the minority of landlords who offer tenants a poor service.
"That's why we have given £6.7 million to councils to use their range of powers to confront rogue behaviour, and why we're changing the law to increase fines.
"Our new How to Rent Guide makes tenants aware of their rental rights and puts pressure on those who are not playing by the rules."