The number of zero-hours contracts has fallen by 300,000 over the past year, official figures reveal.
A survey of businesses in May showed there were 1.4 million contracts that did not guarantee a minimum number of hours, down from 1.7 million, although the share of total contracts remained unchanged at 5%.
The Office for National Statistics said people on zero-hours contracts were likely to be young, part time, female or in full-time education.
Other data found that the number of workers employed on zero-hours contracts in their main job in the three months to June fell by 20,000 to 883,000 compared to the same period a year ago.
TUC general secretary Frances O'Grady said 1.4 million zero-hour contracts was 1.4 million too many, adding: "While it's good that some employers have ditched them as a result of union campaigning, let's not pretend that life at the sharp end has become easier overnight.
"One in 10 UK workers remain in insecure jobs. The spread of low-paid self-employment, agency work and short-hours contracts mean millions are struggling to get by.
"The Government cannot afford to take its eye off the ball. We need more decent jobs in the parts of the country that need them most."
Daniel Tomlinson, policy analyst at the Resolution Foundation think tank, said: "Today's figures provide further evidence that the use of zero-hours contracts is declining in the UK.
"This decline fits with a wider move away from atypical work by many companies, as agency work and self-employment have also stopped growing, and almost all of theemployment growth over the past 12 months is from increases in the number of full-time employees.
"A stronger labour market delivering better job security is good news, but levels of insecure work are still unacceptably high.
"The increase in full-time jobs has also yet to translate into higher pay. Average weekly earnings remain £16 a week below the pre-crisis peak in 2008, so there is still a way to go before we have a labour market that works for all workers."