Thank you for your advice, I have now written to my MP and contacted eBay, I add the content of my letter below. Although I disagree with this new policy I will respect it's terms, but I would hope in time it might be rescinded or at least revised.
I have just had one of my listings for letter opening knives removed because of eBay's new policy on bladed items. Initially I thought this was some kind of funny AI mistake but it turns out it has become actual policy and is related to meeting government requirements. After raising the matter on the community discussions I was advised to contact eBay and the government, so I shall try to explain the issue.
Proof of age
Only people who are 18 or older can buy certain items on eBay, such as knives or other bladed items.
As part of our commitment to the safety of our community, most bladed products and knives can’t be sold on eBay. For bladed items which are allowed, your age will need to be verified.
Bladed products
Crafting tools like rotary blades
Dining cutlery sets that include knives used for eating, such as butter, cheese, fish, or steak knives
Food processors, meat saws, and pizza cutters
Letter openers
Pickaxes and mattocks
Personal care products like manicure kits, dermaplaning tools, and straight razors
Tools such as axes, billhooks, chisels, hatchets, hoof trimming tools, chainsaws, and saws
Scissors
Spears and javelins
Waiter's friend or sommelier knife
Bladed products must be sent using a carrier that provides domestic, age-verified delivery. This needs to be visible on the eBay listing, with sellers selecting only appropriate age-verified delivery services
Underage user policy
Because listings on eBay involve entering into a contract, we require all our members to be aged 18 years or older.
All eBay users have to be over 18 to open an account. ID is required when the account is created. The knives policy page cites this government web page:
But none of the items requiring age verified postage on eBay are listed. Also there are countless everyday items not on either list which could be used as weapons or modified to become one. Sticks and stones can be found on the ground, items are thrown in the bin or skips, there are things all around which are more dangerous.
Age verified delivery is expensive, the cheapest Royal Mail age verified service costs £6.27 for a small parcel sized item, there are no letter or large letter sized options. I was selling a pair of harmless old decorative souvenir letter opening knives with blunt aluminium blades which wouldn't even take an edge, the postage was only £1.55, with this increase it is not even worth selling them. It is unbelievable this is now eBay policy, and there seems to be no clear legal requirement for it either. Several other eBay users in the community discussion pages have described problems too, with items such as lawnmowers, electric jigsaws and windscreen wiper blades being affected. This is going to make many low value items very expensive from a buyers perspective too.
I know knife crime could have a terrible effect on those unfortunate enough to encounter it, but over the years I've seen things go from a situation where there were pretty much no restrictions to this, where we are treated like inmates in a jail, and the statistics show it has made no difference and knife crime continues to slowly increase. I think the core problem to address is the criminal, not the means they use to commit a crime. There is a small percentage of the population which doesn't respond to ordinary logic because they are somehow flawed in their reasoning. Education and persuasion may help but for some it is hardwired into their character, and they commit serious criminal acts unless they are actively prevented, and of course it's difficult identifying them before they commit a crime. Laws and punishment are irrelevant to them, it's like shouting at the deaf or waving at the blind. Perhaps you might get through to some or they might improve as time goes by, but this is why there's an ongoing problem. As the population rises then the level of crime will tend to increase, and they will carry out violent actions by whatever means are available.
The martial arts such as karate were developed because of government prohibitions on various weapons. Many ordinary people also wish to be able to defend themselves, and everyone wants to be able to eat meals with normal cutlery items, cut things with scissors and engage in DIY and gardening tasks. Children must already have access to many of these items at home or school anyway. The gang violence city culture which might influence the judgement of people in the capital has no relevance to most people in the UK, where knife crime is merely another story on the news. I think it would be better to seek measures that deal with the problem where it exists, such as more support for the police, as suggested by this BBC article which also shows most knife crime is committed by over 18's:
Everyone I know has numerous "bladed products" but they never use them for nefarious purposes. If the police were better armed they would be more able to deal with difficult situations when they apprehend miscreants on our behalf, then they wouldn't have to worry so much about this kind of thing.