There is no separate legislation for this, it comes under the UK version of the CPR, along with everything else. You can check this out: [...]
If I have an ETA and thus CE Marking, am I obligated to have an UKTA, if there is no designated standard?
UKCA marking for non-harmonised products are voluntary in the UK, therefore you are not obliged to have a UKTA. << Back to FAQ's
Will the EU accept the information in reverse to ETA/UKTA, so that where a UKTA has been created then a ETA can be applied for?
It is down to the individual EU TAB whether or not to use data generated by a UK Approved Body as part of the issue [...]
If products were covered by ETA and CE was voluntarily applied, does the product then need UKCA Marking because of the CE Mark?
Since 2013 it has been mandatory for any product with an ETA to be CE Marked. It is not mandatory that an ETA is converted [...]
We have an ETA from a European Body and therefore still have a CE Marking in place. Will this now suffice going forward?
We can convert an ETA to a UKTA but UKTAs are voluntory and so it is your choice whether or not to apply for one. [...]
If you sell into the EU, for products covered by a harmonised European Standard, you must continue to apply CE Marking, including using an EU [...]