Rent reduction for inconvenience during Painting / Decorating

Other

I recently had the flat I rent out repainted and the tenants requested a rent reduction for the inconvenience.

The painter said the job would take approximately 5 days.

As they are good long term tenants, I agreed to a 50% reduction in the rent for the week of the painting, as a goodwill gesture.

The painting work subsequently took longer (3 weeks) but the painter said there was minimal disruption during this time. However the tenants are now looking for a 50% reduction in rent for 3 weeks which I have refused.

My question is whether there is any legal aspect to this I need to consider as there is nothing in the Assured Shorthold Tenancy Agreement covering this type of dispute.

Any guidance would be appreciated

Regards
Brian