The landmark achievement comes as the carmaker announces plans to continue working to further raise performance, reduce costs and expand its hybrid product range.

Cumulative hybrid sales reached 5.1 million units at the end of March, including all Toyota, Lexus and other Toyota Motor Corporation-owned brand hybrids sold since 1997, when the first generation Prius was introduced.

In total 20 different hybrids – including the first Toyota plug-in hybrid – are now sold by Toyota Motor Corporation in around 80 countries and regions and the company says this will grow as it plans to introduce 18 new hybrids and a fuel cell vehicle within the next two years.

Within the UK, sales of Toyota and Lexus hybrids are nearing the 100,000 mark since the original Prius made its debut here in 2000. This contributes to a European figure of 544,184 cars sold up to the end of March – more than 10% of the global figure.

Takeshi Uchiyamada, Toyota Motor Corporation vice-chairman, who was responsible for development of the first-generation Prius, said: ‘We developed the first-generation Prius with the aim of making it a car for the 21st century and as an indication of Toyota’s response to environmental issues. We had to develop a hybrid system from scratch, making our task extremely difficult. Nevertheless, we took on the challenge.

‘The launch of the first-generation Prius had effects beyond our expectations, with the vehicle increasing consumer environmental awareness and raising hybrid vehicle expectations. The understanding of consumers at launch time laid the foundation for the widespread adoption, and, since then, consumers have continued to support TMC hybrid vehicles. For this, I am extremely grateful.’

Toyota added that it plans to continue working to further raise performance, reduce costs and expand its hybrid product range.