Support for higher taxes on wealth is popular with millionaires across G20 countries, according to a poll from activist group Patriotic Millionaires. 

It comes as 260 millionaires and billionaires have signed a letter demanding world leaders increase their taxes, coinciding with the World Economic Forum Annual Meeting taking place from 15-19 January in Davos, Switzerland.

Of the 2,300 respondents from G20 countries who hold more than $1 million in investable assets...