Okay, let's take this very slowly. 

1: In pantomimes, the baddie is often called "the Witch" or indeed "the wicked Witch." The goodie is often "the Fairy", "the good Fairy" or "the fairy Godmother".  

2: In Frank Baum's anti-Christian parable "The Wizard of Oz", the heroine Dorothy (accidentally) causes the death of a character called "The Wicked Witch of the East". All the Hobbits are pleased that "The Wicked Witch of the East" has died, because she was wicked. 

3: In the 1939 movie version of "The Wizard of Oz", they sing a song of celebration. It is a very catchy song presumably suggested by the operatic version of "Hansel and Gretel". "The "Wizard of Oz" is the very epitome of camp. It is very much in keeping with this tone that the little people sing a funny happy song when someone dies. 

4: There is also a Wicked Witch of the West and a Good Witch of the North. 

5: Mrs Thatcher was an English politician. She became Prime Minister in 1978 and remained in office until it became clear that she had become insane and was ousted by members of her own party. [The neutrality of his section is disputed.]

6: She died last Tuesday.

7: The Daily Mail Apocalypse Cult, with the full support of Her Majesty's Alleged Opposition, has announced that mourning is compulsory, that anyone criticising T.B.W in any way is part of  "The Left" and therefore an un-person. 

8: The Left, who, on this definition, represent the overwhelming majority, are not bloody having it. They felt that the singing of a happy camp song celebrating the death of a Baddie in a children's movie would be an amusing counterpoint to the compulsory mourning. They bought lots of copies of the record from I-Tunes, in the hope that the BBC would have to play it on the Radio 1 Chart Show which I understand is a bit like Top of the Pops only with fewer paedophiles.

9: The point of playing a camp happy song celebrating the death of a baddie in a children's movie is that it is a camp, happy song celebrating the death of a baddie in a children's movie. The point is not that all females or all female politicians are witches. Neither do the left, on the whole, think that female neo-pagans should have houses dropped on them. Everybody knows that wiccans do not wear pointy hats or fly on broomsticks, in the same way that everybody knows that members of the Society of Friends don't particularly like porridge. 

Lighten up, for god sake, can't you. Bloody Chumbawamba use "ding dong the witch is dead" as part of the soundscape on their Thatcher album. Trying to be more right-on than Chumbawamba is like trying to be more catholic than the bloody pope. 

Actually, "dissent" is completely the wrong word. The overwhelming majority of people either hated her guts or else are totally indifferent to her.

I don't think it is particularly funny, and I think that there are better ways of showing dissent. But I take it for granted that when a Nazi enters the room, every decent person present will claim to be Jewish.

If she were (as those who knew who said she would have wished) having a quiet, private funeral in a   dignified location, attended only by family, close colleagues and maybe one invited photographer then political demonstrations of any kind would be unthinkable. 

Someone would probably still think about them, but they would be unthinkable. 

As it is, her funeral is being orchestrated by the Tory party as a Tory party political event to beatify a former leader of the Conservative Party.

Falklands themed funeral? Falkands themed funeral? With some Chalky White jokes from Jim Davidson, a revue by the Black and White Minstrels and a special celebratory episode of Jim'll Fix It, I shouldn't wonder. The policing of the funeral has actually been code-named "Operation True Blue".

So the question is not "Should we desecrate a private, religious event by holding a party political demonstration?" Of course we shouldn't. I understand that after his assassination, Osama Bin Laden was given as dignified a funeral as possible, according to the tenets of his faith. Myra Bloody Hindley was given a quick, dignified send-off in a municipal crem. [*]

But that is not the question. The question is "Given that the Tory Party has already decided to take what should, indeed, be a private, religious event and turn it into a party political demonstration should the Left a: do nothing or b: have a demonstration of their own to show that no, actually,  there is NO consensus, NO unanimity and that T.B.W is NOT the best loved English person since Churchill." 

Only a complete shit would march into Canterbury Cathedral and disrupt a solemn mass on Easter Sunday because he doesn't like the political views of the Archbishop of Canterbury. But if the Archbishop of Canterbury announced that he was going to hold a special mass to pray that all members of the banking profession should be damned for eternity, followed by the ceremonial excommunication of Sir James Crosby, I think that would probably be the wrong moment to say "I don't think it is right for the Banking Community to complain about what is essentially a private, sacred, religious event." The more strongly the Left threw up a police cordon around the Cathedral and said that dissent had to be prohibited because there was no dissent and everyone agreed with the Bishop anyway except the Right who don't count, the more important it would be for some kind of  counter demonstration to be hold. 

English British Prime Ministers don't generally have big public funerals. Churchill is the last one who did. That was a state funeral. This one technically won't be. The Daily Mail thinks that this proves that the Queen and David Cameron have been infiltrated by The Left. It is an "insult" that T.B.W will only have the same kind of funeral as the Queen Mother and the Princess of Wales, in the same way that is an insult to Christians that vegetarians also have a legal right to have their beliefs respected. (This is perfectly true and not something I made up.)

The whole point of the posthumous exaltation of T.B.W is to manufacture a false consensus. Love of T.B.W and support for the Conservative party, like love of the Queen and support for the Monarchy are not political points of view, they are a base-line neutral position which all British people agree with. [**] If you don't love the Queen, T.B.W and the Tory Party then you aren't British. Once we ignored all the dissenting voices then 100% of those questioned agreed with us. There will be no art, no science, no literature, no enjoyment, no laughter, but the laughter of triumph over a defeated enemy. There will be no love but the love of Margaret Thatcher. 

[*] Cats are to kittens as calves are to cows. "But that's ridiculous, Andrew: have you ever tried milking a cat?" 

[**] What is the British equivalent of Motherhood and Apple Pie? "The Church of England and Steak and Kidney Pie, perhaps?