Art expert Amy Griffin says the Tate Modern should be equipped to restore the mural back to its original state. But how hard that will be depends on whether paint or marker pen has been used.
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A deal is believed to have been reached with official confirmation likely on Friday.
The woman is described as being around 50 years old with short spikey purple hair.
No one gave him a chance - but Donald Trump has just pulled off one of the greatest feats in modern American political history.