Bernie Sanders is expected to gain the endorsement of influential left-wing congresswomen Alexandra Ocasio-Cortez and Rashida Tlaib in the coming days – joining fellow member of ‘The Squad’ Ilhan Omar in backing the senator in his campaign for the presidency.

Ms Omar threw her support behind Mr Sanders after the senator for Vermont appeared in the latest televised primary debate – with the 78-year-old using the stage to dismiss concerns over his health following a heart attack he suffered two weeks beforehand.

Mr Sanders and the Minnesota congresswoman have previously worked together on progressive policies including legislation to provide free school meals to American students and cancel student debt while making higher education fee-free.

“Bernie is leading a working class movement to defeat Donald Trump that transcends generation, ethnicity, and geography,” Mr Omar said in a statement, adding that he was “the best candidate to take on Donald Trump in 2020”.

Meanwhile, Ms Ocasio-Cortez is expected to endorse Mr Sanders at a rally in Queens, New York, on Saturday, according to Sanders campaign officials cited by US media.

Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Show all 15 1 /15 Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez greets fellow lawmakers ahead of the State of the Union address Getty Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez participates in an event with Democratic members of Congress EPA Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures The Democrat senator speaks during a news conference at the U.S. Capitol January 30, 2019 Getty Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez and fellow Democrat Rashida Tlaib AP Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez at the Senate chamber to watch two votes on January 24, 2019 Getty Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez arrives with Chellie Pingree at a House Democratic Caucus meeting Getty Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Ocasio-Cortez during Donald Trump's State of the Union address Reuters Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures New York State Assembly member Catalina Cruz with Ocasio-Cortez AFP/Getty Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Nydia Velazquez talks with Alexandria Ocasio-Cortez Reuters Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Ocasio-Cortez casts her vote for Nancy Pelosi as Speaker of the House EPA Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez poses with a campaign worker during a whistle stop in the Queens borough of New York Reuters Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Ocasio-Cortez outside the US Capitol AFP/Getty Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Ocasio-Cortez after casting her ballot in the 2018 midterm general election at a polling site in New York EPA Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez looks on during a march organised by the Women's March Alliance in Manhattan Reuters Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Ocasio Cortez looks on at the Capitol in Washington, DC, on January 16, 2019 AFP/Getty

The New York representative, who has become a leading light of the American left by supporting ideas including the green new deal and the introduction of a 70% tax on the wealthy, worked as an organiser on Mr Sander’s 2016 campaign.

Rashida Tlaib is also expected to follow suit, according to CNN, potentially leaving Ayanna Pressley of Massachusetts as the only member of the four-congresswoman group left to declare her support for a candidate.

The support of three of the four-member grouping known as The Squad follows a concerted effort by both Mr Sanders and Elizabeth Warren to paint themselves as the Democratic Party’s progressive candidate of choice.

The endorsements could also provide a reviving burst of youthful energy to Mr Sanders campaign amid the concerns over his age and health which caused a slight dip in his poll ratings at the start of the month.

However, the approval could prove to be a double-edged sword – with the group’s outspoken views on a range of issues becoming a subject of attack from conservative voices who have painted them as dragging the Democrats to the left.