It will take the average woman almost 20 years more than her male counterpart to earn her first £1m (€1.4m, $1.5m), further highlighting gender inequality in working Britain.

Financial firm Prudential calculated the average male will have earned £1m before tax at the age of 50 years and eight months. For women, though, they will have earned this amount by the time they are 69 years and seven months.

However, Prudential – which based its research on figures from the Office for National Statistics (ONS) – says the gap is narrowing and over the course of the past year, women have shed nine months off the time it takes to earn the seven-figure sum. Three years ago, the average age for a woman who has earned that amount would have been 72.

For both genders, they would have paid more than a fifth – or £212,300 – in tax before they earn £1m.

Breaking it down by industry, Prudential says those working in finance would pass the £1m mark first at an average age of 41, and the longest would be a food service industries professional who would have to work until they are 94.

Teachers will have to wait until they are 62 to earn their £1m and health and social workers will be 63 by the time they've earned the figure.

Prudential's retirement expert Stan Russell said: "Earning £1m in a lifetime may seem improbable to most people when they start out on the career ladder, but with steadily increasing earnings and longer working lives it is a milestone that is becoming more achievable."