LONDON, England (CNN) -- The BBC is refusing to broadcast a plea from leading British charities for aid to Gaza, saying the ad would compromise the public broadcaster's appearance of impartiality.



Demonstrators protest at the BBC's central London offices Saturday against the broadcaster's decision.



The decision prompted weekend protests in England and Scotland, with one group saying Sunday that 100 people had occupied the foyer of the BBC building in Glasgow, Scotland and would not leave until the BBC runs the ad.



The Disasters Emergency Committee, which includes the British Red Cross, Oxfam, Save the Children and 10 other charities, plans to launch the ad on Monday.



British broadcasters, led by the BBC, originally declined to air the appeal -- but in the face of criticism from government ministers and others, ITV, Channel 4 and Channel 5 changed their minds. CNN was not approached to broadcast the ad, a DEC spokesman said.



About 5,000 people demonstrated in front of the BBC's Broadcasting House in central London on Saturday over the broadcaster's stance. Seven people were arrested.  Watch protest against BBC decision »



In Glasgow, the London-based Stop the War Coalition said Sunday its supporters had moved into the foyer of the BBC building in what the group described as a peaceful protest.



The group did not plan to move beyond the foyer but intended to stay there until the BBC changes its decision, said Keith Boyd, a coalition member who called CNN on Sunday.



"Primarily we are asking that the ad be shown," Boyd said.



The BBC press office would not confirm whether its Glasgow office was being occupied or if protesters were even there.



"We don't comment on individual demonstrations," a statement from the BBC press office said.



The BBC is standing by its decision to not air the ad, director general Mark Thompson wrote in a blog post on the corporation's Web site.



"We concluded that we could not broadcast a free-standing appeal, no matter how carefully constructed, without running the risk of reducing public confidence in the BBC's impartiality in its wider coverage of the story," he wrote Saturday.



"Inevitably an appeal would use pictures which are the same or similar to those we would be using in our news programs but would do so with the objective of encouraging public donations. The danger for the BBC is that this could be interpreted as taking a political stance on an ongoing story," Thompson said.



"Gaza remains a major ongoing news story, in which humanitarian issues -- the suffering and distress of civilians and combatants on both sides of the conflict, the debate about who is responsible for causing it and what should be done about it -- are both at the heart of the story and contentious," he added.



The BBC, which is funded by an obligatory license fee paid by every British household with a television, is required by its charter to be impartial. It does not carry commercial advertising but does broadcast charity appeals.



The DEC is "disappointed that the BBC declined to support the Gaza appeal," the spokesman told CNN. "It might limit the reach of our key message to the general public."



The spokesman, who asked not to be named, said the BBC had to make its own decision about impartiality.



"That is a decision they must make. We have no view on that subject," he said.



Many readers of Thompson's blog post did have a view, however. The statement got hundreds of comments, most of them critical of the BBC.



A commenter who signed in as "bully--baiter" said the BBC was taking a side, no matter what it did.



"Sorry Mr. Thompson but you cannot have it both ways. If deciding to accede to the DEC request would be seen as political then deciding not to accede to it is also political. Don't insult me with your disingenuous attempts to suggest it is otherwise," the commenter wrote.



Other commenters simply rejected Thompson's position out of hand.



"I think the
Who is funded by obligatory license fee? Who refuses to broadcast the ad? Which charity is launching an appeal for Gaza aid? What building are protestors occupying? Which U.K. charity group is looking for Gaza aid? What requires the BBC to be impartial? Where was the building the protesters occupied? What did protesters occupy in Scotland? Who refused to air the ad?
The BBC, BBC The Disasters Emergency Committee, in Glasgow, Scotland Disasters Emergency Committee, its charter in Glasgow, Scotland foyer of the BBC building The BBC
question: Who is funded by obligatory license fee?, answer: The BBC, | question: Who refuses to broadcast the ad?, answer: BBC | question: Which charity is launching an appeal for Gaza aid?, answer: The Disasters Emergency Committee, | question: What building are protestors occupying?, answer: in Glasgow, Scotland | question: Which U.K. charity group is looking for Gaza aid?, answer: Disasters Emergency Committee, | question: What requires the BBC to be impartial?, answer: its charter | question: Where was the building the protesters occupied?, answer: in Glasgow, Scotland | question: What did protesters occupy in Scotland?, answer: foyer of the BBC building | question: Who refused to air the ad?, answer: The BBC