Why we don't sell part worn tyres

A survey carried out by TyreSafe found that up to 98 per cent of used tyres sold in Britain did not comply with the regulations, while 34 per cent could be considered dangerous.

Source https://www.autocar.co.uk/car-news/advice/part-worn-tyres

Buying a part-worn tyre is much like buying a second-hand electrical product - you don't have any comeback if there is something wrong with it, and if you have an accident that can be squarely blamed on the fitting of part-worn tyres, then you don't have any legal comeback if you want compensation.

Source https://www.autoexpress.co.uk/car-news/consumer-news/86584/six-million-unsafe-part-worn-tyres-uk-roads

The National Tyre Distribution Association (NTDA) has claimed that "as many as 97% of all part-worn tyres are being sold illegally", with lax attitudes to (and poor enforcement of) the regulations surrounding part-worn tyres.

Source https://www.carbuyer.co.uk/tips-and-advice/156275/what-are-part-worn-tyres