‘Thomas The Tank Engine’ has undergone the biggest update in the children’s favourite’s history after years of accusations of sexism, racism and classism.

The TV show, based on the books by Rev Wilbert Awdry, will be relaunched next week with new multicultural and gender-balanced characters, 73 years after it was created.

‘Thomas & Friends’ will now feature Isla, an Australian Flying Doctor; Hong-mei, A Number 1 Blue Tank Engine from China, and Churubala, a female railway controller from India.

This means the Steam Team is now gender-balanced, with three male and three female characters: Percy, James, Gordon, Emily and new characters Nia and Rebecca, as well as Thomas.

Thomas will also leave the island of Sodor to meet new trains, as part of a bid to expand the series’ global appeal and promote “sustainable development goals” in partnership with the United Nations.

The ‘major strategic brand refresh’ was designed after market research was carried out with hundreds of children and parents around the world.

It’s hoped the relaunch will appeal to female viewers, after research showed that girls represented over 40 per cent of the show’s viewership.

Ian McCue, Senior Producer at ‘Thomas & Friends’, says: “The show has undergone an evolution to remain relevant for the next generation of parents and children by opening up the world of Thomas & Friends so children can discover the world around them while being entertained.

“The changes and new additions of characters and geographies will make the show more entertaining, inclusive and global – whilst ensuring all the favourite characters and storylines that fans around the world love remain at the heart of the action”

Controversially for some older fans, the beloved Thomas theme tune has been updated too, but will still be included in some musical segments in a number of episodes.

The new series of ‘Thomas & Friends: Big World! Big Adventures!’ will air daily from Monday 3 September at 7am on Channel 5 Milkshake!.