Boris Johnson asked the Chancellor George Osborne "to look at the baleful effects of stamp duty" in London and elsewhere during his conference speech.
The Mayor of London told the Conservative Party conference: "It's called stamp duty for a reason, because it's stamping on the fingers of those who are trying to climb the property ladder.
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The victims were playing the popular game in Whittington Park in Holloway on Tuesday night, when three males suspects approached them.
A former Royal Marine who has recently been engaged has been killed in a climbing accident in the French Alps.
Through the day we'll see plenty of sunny spells but there will be a risk of showers too as they filter down from the northwest.