The majority of Americans back an impeachment inquiry into President Donald Trump, according to new polling.

At least four polls have been taken since Nancy Pelosi, the House Speaker, announced the chamber would begin a formal investigation into the US president.

Three of the surveys show clear support for impeachment, while a fourth is tied.

A Huffington Post poll of 1,000 US citizens found that 47 per cent believed that Mr Trump should be impeached and removed from office, while 39 per cent did not.

A poll by Business Insider garnered similar results, with 45 per cent of respondents saying they supported impeachment, including 29 per cent who said they were "strongly" in favour of the move. Meanwhile 30 per cent said they opposed impeachment, with 20 per cent of respondents saying they "strongly" opposed it. There were 1,096 respondents in total.

A new PBS/Marist poll published on Thursday found that 49 per cent of American adults now approved of a formal impeachment inquiry, with 46 per cent disapproving and 5 per cent unsure. This compared to a similar poll in May, in the aftermath of a report into the Russia investigation, which found that 53 per cent said they did not want Mr Trump to be impeached. The NPR/PBS NewsHour/Marist Poll was conducted by telephone on Wednesday and talked to 864 adults.