Almost one in five jobs in London is classed as low pay, a slight fall compared with recent years, a study shows.
Around 720,000 jobs in the capital are low paid, twice as many as a decade ago, said the New Policy Institute (NPI).
Fewer than a third of part-time jobs in London were low paid in 2006, but that figure has jumped to 43%, the research found.
The boroughs with the highest proportion of jobs paying below the London living wage were all in Outer London, including Bexley, Harrow, Enfield, Sutton and Waltham Forest.
Around 27% of low-paid jobs were in retail and wholesale, with a fifth in hotels and restaurants, said the report, funded by charitable foundation Trust for London.
Adam Tinson, senior researcher at the NPI, said: "No further increase in the proportion of low-paid jobs in London is welcome.
"However, low pay rates are still higher than a decade ago, and particular employment sectors have a very poor record that must be addressed."
Mubin Haq, of Trust for London, said: "London has seen a significant growth in jobs over the last few years.
"Unfortunately, too many are low paid.
"This data shows that whilst there has been a halt in the rise in low pay, there is still a long way to go to making sure Londoners are paid fairly.
"Nearly 3,000 employers have committed to paying a living wage, with more than 1,000 in London accredited with the Living Wage Foundation.
"That's a great step in the right direction but many more need to sign up.
"Not only is it good for employees but it's also good for companies, with clear evidence that retention rates improve."
Child Poverty Action Group chief executive Alison Garnham said: "If ever there were evidence that our capital city isn't working for everyone, it's in these findings on low pay.
"With a fifth of London jobs now low paid - most of them done by women - it's little wonder that most children in poverty are now in working households."