Why hotter summers are making British potatoes smaller

"There will be fewer potatoes grown going forward. They are a very expensive crop to grow," says Tim when the BBC visits his farm near Helmsley.

"There's less enthusiasm to have the expense of growing that crop when we have some sort of climate change hitting us year after year after year. We're nearly getting to the stage where enough is enough.

"Most potatoes require 200ml of rain or other water and this year they've had about 35ml. It's also been incredibly warm. Potatoes don't bulk up above 28°C. I think we've had 40 days above that."

It's a similar story of falling crop yields near Selby, where farmer Richard Bramley would like the government to provide interest-free loans to farmers so they can invest.

"We think our potatoes will be 20 to 25% down," he says.

"We have to generate the income not just to live, but to produce the following year's crop. That's the dilemma so many farmers find themselves in a the moment.

"Off the back of two, maybe three really bad years, the resilience in the farming industry is starting to break down. I think we certainly have a problem, quite when it will really manifest itself I am not entirely sure."

A statement from the Department of the Environment, Food and Rural Affairs (DEFRA) confirmed the issue is on Andy Burnham's desk.

"Food security is national security and one of the Prime Minister's first visits was meeting farmers hit by drought and dry weather, announcing a £65m package."

It added: "We're going further to address the risks of climate change and nature loss - including a new taskforce to strengthen climate security."

Scott Walker, chief executive of growers' association GB Potatoes, said shoppers should expect fewer large varieties of potato on the shelves this year.

"The prolonged hot and dry weather placed significant pressure on the British crop and has restricted the growth of potatoes. With harvesting still under way, we will not know the full impact until the crop has been lifted, but as well as fewer potatoes there will be fewer large potatoes this year.

"Consumers are likely to notice this most with baking potatoes, where the sizes available will be smaller than usual.

"The supply chain is extremely good at making the best use of the crop that is available, so consumers will continue to find good quality potatoes and potato products that are good value for money."

Back in Helmsley, Tim Rooke wants changes to planning laws to make it easier to build and run water storage lagoons, capturing winter rain and using it in the summer.

"We need a more relaxed attitude to allow this to happen.

"This is our third bad harvest in five. The weather has certainly altered in this area. We have to adapt and it's time we started or we're going to end with not many potato farmers left in this country."