Elon Musk asks Twitter followers whether he should sell $21B worth of shares in Tesla

Tesla CEO Elon Musk is asking on Twitter whether he should sell 10 percent of his stock in the electric-vehicle company amid pressure in Washington to increase taxes on billionaires like him.

Some Democrats have been pushing for billionaires to pay taxes when the price of the stocks they hold goes up, even if they do not sell any shares. It is a concept called "unrealised gains" and Musk is sitting on a lot of them with a net worth of roughly $300 billion.

"Much is made lately of unrealised gains being a means of tax avoidance, so I propose selling 10 percent of my Tesla stock," he tweeted on Saturday afternoon. "Do you support this?"

The poll received near two million responses in seven hours after he posted it, with 55 percent of respondents approving the proposal to sell the shares, according to a report by Reuters. The poll is scheduled to end around 3 pm ET (2000 GMT) on Sunday.

Much of Musk's wealth is held in shares of Tesla, which does not pay him a cash salary. "I only have stock, thus the only way for me to pay taxes personally is to sell stock," he tweeted.

Musk said that he will abide by the results of the poll, whichever way it goes.

Musk's shareholding in Tesla comes to about 170.5 million shares as of June 30 and selling 10 percent of his stock would amount close to $21 billion based on Friday's closing, according to Reuters calculations.

Musk has criticised the proposal, which would affect 700 billionaires and impose taxes for long-term capital gains on tradable assets, whether or not they have been sold.

In September, Musk said he is likely to pay taxes of over half the gains he would make from exercising options.

He also dismissed the possibility that he would take loans with his Tesla shares as collateral.