Biden was announced as the president elect on Saturday after Pennsylvania and Nevada declared the Democrats had won their electoral college votes, bringing him to 290 overall. He needed 270 votes in the electoral college to win the presidency.

In a tweet on Sunday, Trump repeated claims that the election had been ‘stolen’, adding that the “best pollster in Britain wrote this morning that this clearly was a stolen election, that it’s impossible to imagine that Biden outran Obama in some of these states”.

Trump was referring to Patrick Basham, director of the Democracy Institute, who has written for the Sunday Express newspaper throughout this year’s US election. The Democracy Institute is a public policy research organisation based in London and Washington DC.

The Trump campaign has not produced any evidence to show Biden’s victory was illegitimate, and his claims of widespread voter fraud have been rejected by officials in the affected states.

Despite this, Trump’s campaign team has launched numerous lawsuits against the results, many of which have already been dismissed by the courts. Twitter has also labelled Trump’s tweets claiming electoral fraud as “disputed”.

In his column in the newspaper on Sunday, Basham repeated claims by the president that “there is a mountain of evidence, direct and circumstantial, of widespread ballot fraud”.

In his article on Sunday, Basham said that his polling techniques focused on surveying “likely voters”, and has polled Biden and the Democrats consistently below many other polling companies, and had suggested Trump was on course to retain the presidency.

Basham’s weekend column claimed: “I wrote last Sunday that, should our Biden popular vote projection be off by a couple of points, it would reflect voter fraud rather than our having missed a Biden landslide. My words were prescient.”

Joe Biden will be inaugurated as the 46th US president on 20th January.