Bigpower

i have had to sacrifice the passenger seat belt to get my harnesses in today ( will update the slag's thread in due course )

but knowing i will have to repeat this on my side, what is the law on no retractable seat belt but a 4 point harness set up?

would i have to re-MOT my car?

If they are "E" marked they are fine.
As far as I am aware harnesses with an aircraft style buckle release are not "E" marked, and those with a regular style belt release are.
Out in the big wide world you would probably get away with them at MOT time but at a pedantic garage it would be a fail.

Think its road legal as long as the buckle release mechanism on the harness is not a quick release or twist lock :!:
AFAIK as long as the harness has a push button release its legal
Most harnesses ( or they used to) state whether they are road legal or not :?: :!:

:? they are seat belt style release clips but not sure about any "E" mark?