THE BBC has banned the controversial anti-Thatcher song, Ding Dong!

The Witch is Dead, from being broadcast in full as fears grow over violent clashes at a protest against the former prime minister tonight.

Just 24 hours previously the BBC idicated the 1939 song from the Wizard Of Oz would be played as part of Sunday's chart show but the corporation has now said, following protests, that only a clip of "up to five seconds" will be used in the programme.

Tony Hall, facing his first major challenge as the BBC's new director general, branded the use of the protest song "distasteful and inappropriate", but made clear a section would still be broadcast tomorrow. Yesterday, it was expected the song would move to the No 1 slot in the official charts by Sunday. It is the No 1 selling track on iTunes.

Lord Hall said: "I understand the concerns about this campaign. It is distasteful and inappropriate. However, it would be wrong to ban the song outright as free speech is an important principle and a ban would only give it more publicity."

The climbdown comes ahead of a planned protest and feared violence in London's Trafalgar Square today, where thousands have vowed to "celebrate" the death of Lady Thatcher at the landmark, scene of the poll tax riots of 1990.

In Scotland, police are monitoring groups who plan to hold parties in Edinburgh and Glasgow this evening to celebrate the death of Baroness Thatcher.

On the decision to limit the song's broadcast to a few seconds, Lord Hall said he had spoken to Ben Cooper, the controller of Radio 1, which broadcasts the chart show, and had agreed "we won't be playing the song in full, rather treating it as a news story, and playing a short extract to put it in context".

Mr Cooper admitted to being "caught between a rock and a hard place", explaining how there were emotional arguments on both sides.

He said: "On one side, there is the understandable anger of large numbers of people who are appalled by this campaign.

"On the other, there is the question of whether the chart show – which has run since the birth of Radio 1 in 1967 – can ignore a high new entry which clearly reflects the views of a big enough portion of the record-buying public to propel it up the charts."

John Whittingdale, Conservative chairman of the Commons Culture Committee and a former parliamentary aide to Lady Thatcher, initially said the protest song should not be played, but by last night supported the way the BBC had decided to deal with what he conceded was a difficult issue.

Yesterday evening, the controversy over the Judy Garland song had spread to Ireland, where it went into the charts at No 33.

In contrast, a campaign was launched by a Facebook group opposed to the anti-Thatcher protest, urging people to buy the song I'm In Love With Margaret Thatcher, a 1979 punk single by the Notsensibles.

Meanwhile, a poll by TNS BRMB illustrated how the former prime minister, who died on Monday following a stroke, continues to be a divisive figure with the strongest opposition to her being in Scotland.

Asked if Britain needed a leader like Lady Thatcher to lead it to economic growth, 40% of 1200 adults questioned agreed while 33% disagreed. Asked whether she had had a good or bad effect on the nation, 41% said good and 34% said bad.

There was also a clear north-south divide. The biggest opponents of the late premier were in Scotland, where only 18% agreed that Britain needed a leader like Lady Thatcher and 46% disagreed. In contrast, the largest support was in Greater London where the respective figures were 49% and 23%. Even among Labour voters, one in five agreed the country needed a PM like Mrs Thatcher while almost half of LibDem voters also agreed as did almost nine out of 10 Tory voters.

At the Unison health conference in Glasgow, delegates applauded a description of Lady Thatcher as "an evil person", who ruined communities.