I checked it in a browser without an ad blocker. TWO overlay (one after the other) that covered the entire content of the page. Then ads, ads, and more ads in the content.
I get that the BBC needs to make money to produce content. But what good does it do for an advertiser to have ads be so annoying that people without ad blockers are just closing the page? What good does it to for an advertiser to be one of ten different brands being advertised on the same page?