The MP for Wells in Somerset is due to lead a half-hour debate in the House of Commons today over the amount of sugar in jam. Ministers are hoping to relax the rules governing minimum sugar levels, allowing it to fall from 60 percent to 50 percent, saying it will help British producers trade abroad.
Munt, though, says she fears that the change could mean the end of the British breakfast as we know it, with jam and marmalade becoming runnier and their shelf life shorter. They could become like "coloured mud," she says.
"At the minute, we've got a jam that we know exactly what it's like. It's a fantastic colour, a really good shelf life - it's going to last a year - it's beautiful consistency, it's got a gloss to it," she told the BBC.
"If these regulations change, we'll end up with something much more like the French and German product - and worse still the Americans - where they have things a bit like a fruit butter or a fruit spread. It's dull colours that don't taste the same and they certainly don't last as long."
"The proposals do not state a jam has to be made at a lower sugar level, it just gives industry the flexibility to produce one at such a level," it says. "This, we believe, takes account of a wider variety of products now on the market an technological innovations which allow jam to be produced at a lower sugar content without the need for preservatives which are not permitted in jam."
But the proposals are also opposed by Rosemary Jameson, an artisan jam maker and founder of the Guild of Jam and Preserve Makers. Indeed, she says, the changes could cause a health risk, as lower-sugar products would need to be stored in the fridge - something consumers might not be aware of.
"What I actually object to is that any product in future will be able to be called jam - currently, anything below 60 percent sugar is labelled 'reduced sugar jam'," she says. "I don't see that there is any reason to mess with that, because it's clear for the consumer."