Newham Council has received license applications from 30,000 private landlords as part of its pioneering scheme to improve housing conditions in the borough.
Since January 1 this year, the council has carried out 750 enforcement visits, issued 1,200 warning letters, and handed out 50 cautions. Thirty prosecutions, at various stages of the legal process, have been pursued since the scheme started.
Private landlords who have failed to apply are committing an offence - and could face fines of up to £20,000 per property.
Newham is the first council in the country to implement a scheme to license all private rented properties.
The council has consulted extensively with residents, stakeholders, private sector tenants, landlords and lettings agencies. 74% of residents and 76% of private tenants supported the borough-wide licensing scheme.
The radical move came after the borough announced the creation of a task force to combat 'sheds with beds', illegal ramshackle buildings built at the bottom of gardens which often house tenants living in appalling squalor, exploited by rogue landlords.
The scheme is backed by national housing charity Shelter and other councils are considering following Newham's lead.
The pioneering initiative has already been successfully piloted on a small scale in the borough's Little Ilford Neighbourhood Improvement Zone (NIZ). The pilot scheme achieved 100% compliance following enforcement action against a number of non-compliant landlords.
Newham Mayor Sir Robin Wales said: "It is clear from our consultation that our residents, including tenants in private sector homes, massively back our plans.
"This scheme shows that Newham is leading the country when it comes to tackling bad landlords who flout the law.
"We want to ensure that private sector rented properties are well managed and meet a good standard. We also want to deal with the crime and anti-social behaviour that is sometimes associated with bad private sector rented housing.
"There are good landlords in Newham and we want to work with them. Unfortunately there are also some unscrupulous ones - which these proposals would target."
Sir Robin added: "We will never accept private sector tenants being directly exploited by landlords who force them to live in dangerous and unacceptable conditions.
"Good landlords have nothing to fear from this scheme. For the bad ones, this a clear message they must clean up their act - or pay the price.
"One bad house can drag down a whole street. We are doing this for the community."
Kay Boycott, director of communications, policy and campaigns at Shelter, said: "We are delighted to hear that Newham Council is introducing this scheme, which will help protect vulnerable tenants from rogue landlords who are making their tenants' lives hell.
"With a chronic shortage of social housing and more and more people being priced out of the housing market, renting is fast becoming the only option for thousands more Londoners. Our advice service for tenants in Newham sees people every day who are suffering at the hands of rogue landlords who are ignoring their responsibilities and wreaking havoc on tenants' lives.
"We urge other local councils to follow Newham's lead in sending a clear signal that enforcing the law against rogue landlords is a priority."