Yes if it goes via a fused spur unit. All before fused spur unit is 2.5mm and after the FSU you can if the reading permit reduce to 1.5mm.
Of course you need to check ELI and RCD tripping times and currents and all the other details required when filling in the minor works certificate and without the details contained in that form it would be impossible to be certain as to if you can use 1.5mm with the spur you intend.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local