Every parent’s dream: Expandable children’s shoes that fit long enough to be worn out are on the way

Founder Jeroo Doodhmal said the mechanism could double the shoes’ lifespan. Young children’s shoe sizes change roughly three times a year.

The out-of-the-box idea is being funded by John Lewis, which gave Pip & Henry £250,000 via its £1million eco fund.

Ms Doodhmal, 38, told The Guardian: ‘I think we’re about a year away from it being in the shops.

‘We have to test the prototypes and then take it to industry experts for their feedback … then come up with a final concept that’s ready for commercial launch.’

Pip & Henry’s sustainable shoes for children cost £60 – and the expanding range would likely cost £20 more, the founder said.

‘It is my ambition to keep the cost down as much as possible’, she explained.

The entrepreneur got the idea while watching Blue Planet with her baby daughter.

She said: ‘On the one hand I was showing her Blue Planet, and trying to get her inspired by nature, but on the other, she was outgrowing clothing and footwear faster than I could effectively recycle it.’

Design proposals include an extendable sole with an interlocking, jigsaw-style mechanism.

‘The funding is substantial enough to take us all the way,’ Ms Doodhmal added.

‘I feel very confident we will be able to come up with something really valuable and robust.’

Brits purchase 80million pairs of shoes each year – including 60million for children.

More than 85 per cent end up on landfill sites, Ms Doodhmal said.

She said: ‘We won’t move the needle on that 85 [per cent] if we don’t take this concept to the mass market.

John Lewis sustainability director Marija Rompani said the Circular Future Fund, which has also given money to Scottish libraries and the University of Leeds, could have ‘real impact’.

She said: ‘Our throwaway culture, and the waste it generates, are unquestionably among the biggest challenges we will face in our lifetime and tackling them will require a different kind of thinking.’