Donald Trump would lose 2020 presidential election to Bernie Sanders or Joe Biden, new poll suggests

Senator Elizabeth Warren also beats incumbent in latest survey, as 53 per cent of voters still want Obama in the White House

The polling will encourage Sanders supporters (Getty)

Donald Trump would lose to Bernie Sanders and other Democrats in a 2020 Presidential election, according to a new poll.

The incumbent would lose by 13 points — 52 per cent to 39 per cent — and by an even greater margin against former Vice President Joe Biden, Public Policy Polling (PPP) found.

The Democrat-aligned firm tested voters' preferences for a string of potential opponents for Mr Trump.

The billionaire would also lose to Senator Elizabeth Warren by a seven-point margin, it found in a survey of 836 registered voters.

Its poll had a margin of error of 3.4 per cent.

Mr Sanders, the Vermont senator who lost the Democratic presidential nomination for the 2016 election to Hillary Clinton, has been a fierce and outspoken critic of Mr Trump's administration and particularly its stance on healthcare.

Rumours have swirled around Mr Biden after the launch of a political action committee — a fundraising vehicle — he announced earlier this summer, called American Possibilities.

Mr Trump named Ms Warren as a potential rival in the 2020 during a speech to the National Rifle Association.

PPP also found that more than half of voters — 53 per cent — wished Barack Obama were still President. Forty-nine per cent favoured Hillary Clinton.