No idea if this is correct or not (from here)
Asbestos disclosure when selling a house in the UK
Since the repeal of the Property Misdescriptions Act in 2013, all sellers are obliged to disclose the presence of asbestos during a sale. Of course, owners are not expected to detect the presence of asbestos in their home by themselves, but more than likely this information will have been uncovered by a chartered surveyor before they moved in.
In a large majority of cases, a seller will also be using a surveyor to determine the value of their home prior to placing it on the market, and their estate agent of choice will likely query the presence of asbestos based on the age and construction type of the property. Generally, any home built before 1978 could contain the toxic material, and a failure to detect the presence of asbestos in these instances could open up both the surveyor and agent to prosecution.