The Conservative mayor urged all employers in the capital to follow the GLA's lead and "pay a fairer wage" to those working and living in the capital as he outlined a 3.3% rise in the unofficial minimum wage for Londoners.
The living wage reflects the fact that those working and living in the capital need an hourly wage rate set at 17% above the national minimum wage rate of £5.80 to take them above the poverty level.
Johnson has no powers to impose the proposed wage on London businesses, but has previously made the moral case for a decent wage, which he argues helps companies retain a motivated and productive workforce as well as encouraging those on benefits to take up employment.
The Greater London authority published the Living Wage Unit's sixth annual report, A Fairer London: The 2010 Living Wage in London, which identifies what the living wage should be in light of the fact that the cost of living in the capital is higher than that the rest of the UK.
Using a range of indicators, it finds that someone paid less than about £6.80 an hour in the capital will be living in poverty, even after benefits and tax credits are taken into account.
The rate has seen an overall increase of 17% since it was first introduced by Johnson's predecessor, Ken Livingstone, in 2005 at £6.70 per hour, following lobbying from the London Citizens charity. David Cameron raised eyebrows during the general election campaign when he wrongly claimed that Johnson had pioneered the living wage, in an article in the Guardian.
The mayor has, however, championed the living wage since taking office in 2008. He has written to major employers across the capital outlining the business case and social benefits of implementing it and urging them to pay this figure.
Johnson revealed today that five new large employers have agreed to pay the rate as a minimum: Clifford Chance, Deloitte, Nomura, Prudential and Standard Chartered. They join just under than 100 organisations already committed to pay the rate, as well as London boroughs such as Ealing and Tower Hamlets.
Johnson said he was determined to ensure that the capital remains an "international, diverse, competitive and socially cohesive city".
"The capital relies on the work of many who carry out the city's essential functions on a daily basis – from office cleaners to care workers in social services. It is right that their skills and commitment to London's success are recognised, and one of the most fundamental ways of doing this is to ensure that all Londoners are paid properly.
"That means receiving at least the London living wage, which is designed to combat poverty and also ensure that people are better off in work than out of work.
"The success of the London living wage depends on the extent of its acceptance by employers. There are huge benefits to employers and society of implementing the London living wage and today I urge all employers in the capital to follow the GLA's lead and pay a fairer wage."
City Hall claimed that all organisations within the GLA group (London Development Agency, Transport for London, London Fire and Emergency Planning Authority, Metropolitan police authority and the Metropolitan police service) are paid at or above the living wage.
This includes all new contracts for staff working on GLA sites, such as caterers, security guards and cleaners "where allowed".
London Citizens, which has spearheaded the LLW campaign, welcomed today's 3.3% rise.
Reverend Paul Regan, a trustee of the group, said: "In these tough economic times, the living wage is even more important to keep hardworking Londoners out of poverty. The fact we have more and more companies becoming living wage employers goes to show that the living wage is becoming the real minimum for London's responsible businesses."
An independent report published last year showed that a higher proportion of people of all ages live below the poverty line in London than in other regions.
London's poverty profile, compiled by the City Parochial Foundation and the New Policy Institute, suggests housing costs account for much of the difference between poverty and inequality levels in London, which has a population of 7.56 million, and the rest of the country.
Child poverty overall has remained unchanged since the late 1990s, but is rising in households where at least one adult is working.
London Councils, the umbrella body for London's 32 local authorities, said it understands that all London boroughs are already paying their own members of staff the London living wage.
But this was disputed by the Green party on the London assembly, which pointed to information secured under a freedom of information request which revealed that at least 165 directly employed council staff in London are still paid less than the London living wage.
The London Borough of Merton confirmed that it directly employs 165 staff who are paid less than the London Living Wage. The council was Tory-led until the May local elections, and is now led by a minority Labour administration. But the council's chief executive, Ged Curran, insisted most boroughs had staff earning below the London Living Wage. He said: "Merton recognises that the cost of living is higher in London and this is reflected in the way salaries are set in the borough. The current system for evaluating pay grades does leave some staff on a grade below the London Living wage and this is a matter that the council is currently reviewing."
Darren Johnson, a Green assembly member, said: "Five years on it is shameful that most boroughs still have cleaners, carers and park wardens working below the bread line."
Just eight London councils are also committed to encouraging their contractors to pay staff the rate judged necessary to ensure people are not living on poverty wages.