Margaret Thatcher art posters banned from Tube
Posters of Margaret Thatcher due to be shown at Westminster Tube station have been banned by advertising bosses.
Six portraits of the former prime minister, including a depiction of her as Queen Victoria, were due to run from this week.
CBS Outdoor, which sells advertising space across the London Underground, said running them would break Transport for London (TfL) guidelines.
Former Culture Secretary David Mellor said it was a "stupid situation".
Ben Moore, of Art Below, said he hoped the decision would be overturned.
The portraits were initially shown in an exhibition at Gallery Different in central London, which opened last Wednesday, the day of Baroness Thatcher's funeral.
They included a pastiche of Peter Paul Rubens' The Assumption of the Virgin Mary with Baroness Thatcher's face replacing Mary's.
They were due to be placed on advertising boards at the station nearest the House of Commons after the Tube closed on Monday.
But a spokeswoman for CBS Outdoor said the artwork contravened advertising policies.
She said: "If an advert has messages or images that relate to public controversy or sensitivity it will not be run."
She said the advert had not been referred to the independent regulator, the Advertising Standards Authority (ASA).
Under its copy approval policy, CBS Outdoor says it reserves the right to refuse a poster design without providing specific reasons.
It says: "CBS Outdoor will endeavour to refer to the guidelines laid down by our franchise partners, who include London Underground, London Buses and all of our other bus, rail and tram franchises."
A statement from TfL said: "Our advertising contractor took the view that it could have been considered insensitive to have displayed the posters at the time of Baroness Thatcher's funeral.
"As her funeral has passed, they will be happy to consider them again."
Mr Mellor, a former colleague of Baroness Thatcher's told BBC London the posters were "totally inoffensive".
He said: "I'm amazed that we get ourselves into this stupid situation where we cannot show these posters in Westminster Tube station, immediately adjacent to the Palace of Westminster, because in a kind of sad bit of reverse colonialism we've given an American company owned by CBS the right to veto these things.
"What's the matter with this country?"
Mr Moore, of art organisation Art Below, said it had not been his intention for the posters to run last week.
He said: "I remain hopeful that these images will eventually conform to the guidelines, or the guidelines will evolve to reflect a more democratic state."
He added he wanted people at Westminster Station to enjoy a "refreshing alternative of the Thatcher icon".
The posters are among a number of art pieces regularly placed on advertising boards on the underground by Art Below.
Last month, the High Court ruled TfL was right to ban an advert suggesting gay people could be helped to change their sexuality.
It was due to run on London buses as a response to an advertising campaign by gay rights group Stonewall.
TfL successfully argued it breached its advertising policy by containing a controversial message "likely to cause widespread offence to the public".
Mrs Justice Lang said although she did not think an appeal would succeed, there were "compelling reasons" to allow one to go ahead.
She said the case "concerns interference with the right to freedom of expression which is a matter of such fundamental importance that it merits consideration by the appellant court".