The proportion of working mums which children aged three and four has increased by almost 10 percentage points over the past two decades, according to the Office for National Statistics.
In England there are now around 133,000 more mothers, whose youngest child is a toddler, in employment in 2017 (65.1%), compared with 1997 (55.8%).
The ONS says the rise in overall employment for mothers has been driven mainly by an increasing number working full time. The proportion of mothers working part time when they have young children has remained relatively static over the period, although it remains much higher than those working full time, according to the figures.
However, the ONS says mothers with young children have the lowest employment levels of all parents with dependent children at 65.1%. In comparison, the employment rate of fathers with children aged three or four is 93.2%.
There has also been a significant increase in the number of fathers who have young children working part-time – it has almost doubled from 3.9% in 1997 to 6.9% in 2017, but is still well below the proportion of women with young children working part-time – 38.2% in 2017. Generally, the rate of men with young children working full time has remained stable.