The housing charity lined the station's exit walls with an eight-poster strip and placed individual posters along its platform edge last Thursday to mark the start of the home and lifestyle exhibition the following day.
The pictures of bad housing provoked an angry response from event organiser DMG (Daily Mail Group) World Media, which called them an "attack on the exhibition" and telephoned the charity to demand that they be taken down.
But Adam Sampson, the charity's director, said the posters would stay up until 20 October, as agreed with London Underground.
"Shelter has not attacked either the organisers or visitors to the Ideal Home Show," he said. "Of course we think people should enjoy making a comfortable home for themselves, but we want to focus the spotlight on the contrast between this and the suffering of more than 1 million children in Britain today due to bad housing."
London Underground withdrew permission for Shelter to hold a photocall of Big Brother contestants in front of the ads last Friday. It was held on the street instead.
The posters were backed by ads in the national press, and a nationwide billboard campaign.