Madonna has sold 17 million singles in the UK compared to Kylie's 10 million, she has 13 UK number one singles compared to Kylie's 7. She's also sold around 20 million albums in the UK. She's the fourth best-selling artist of all time in both total singles and albums sold. The Immaculate Collection was also the biggest selling album by a female artist until Adele's 21 overtook it. Madonna also has more top five hits than any other artist (if you don't count the re-releases after Elvis' death), she also has more top ten and twenty hits than any other female.
With MDNA she racked up her 12th UK number one album, more than any other solo artist. Kylie is way behind with 5 number one albums. During the 00s Madonna had 5 UK number one singles, Kylie had 3.
I understand that you prefer Kylie, but that doesn't mean that she's more popular in the UK than Madonna. The statistics prove otherwise.
Even if Madonna never has another UK number one single or even a top ten hit again Kylie won't ever get close to matching her overall sales or chart success, I do believe that Madonna's single sales are past their peak but Kylie is entering that stage too. It's a sad reflection of the ageist and sexist world we live in.
.....also to add to my earlier post it seems only when Madonna released her celebration greatest hits that washer most successful most recent album in lets say the last 7 years or so. Its seems the public only like old Madonna in the auk not her new stuff