The Conservatives are investigating election candidate Sally-Ann Hart for alleged Islamophobia just days after opening an inquiry into her for liking a Nazi phrase on Facebook and sharing an antisemitic slur.

Labour has made fresh calls for the Tories to suspend their candidate in the marginal seat of Hastings and Rye, who was also publicly condemned last week for implying that disabled people should be paid less than the minimum wage because they do not understand money.

The latest allegations relate to a post that Hart shared on her Facebook wall in 2017, in which she described a blog by anti-Islam activist and author Cheri Berens as an “affecting read”.

In the blog, Berens claimed the Women’s March against Trump in the US had been used to promote the “Muslim agenda” in the US and that the Muslim Brotherhood had hijacked the movement.

She claimed this was because they want American women to have abortions to limit the non-Muslim population, adding that American women should not wear the headscarf and wherever it is worn in the world there is oppression.

Berens also claimed that the Muslim Brotherhood, a transnational Islamist movement founded in Egypt, want to destabilise American youth and that they control the media.

A Conservative spokesperson said: “Sally Ann Hart is under investigation and these comments will form part of that investigation.

“Our complaints process is rightly a confidential one but there are a wide range of sanctions to challenge and change behaviour, including conditions to undertake training, periods of suspension and expulsion, and these are applied on a case-by-case basis.”

Boris Johnson has claimed that any of his candidates found to be discriminating against people would be “out first bounce”.

Hart has not been suspended pending an investigation into alleged antisemitism and continues to stand for the Tory-Labour marginal seat which was previously held by former work and pensions secretary Amber Rudd.

Berens’ blogpost said: “[The Muslim Brotherhood] want American women to have abortions. They want the non-Muslim population to be stagnant while their Muslim population grows. Numbers mean power.”

“They want a young male population that is weakened or with confused female tendencies, whether real or imagined, or transgendered. They want to oppress the women and weaken the men. And the rest of America? They are controlling you via the media.”

She claimed the Women’s March was not about Trump but used as a scapegoat for the Muslim agenda in the US.

Hart shared the post on 25 January 2017, shortly before she was selected to stand in Durham North West at that year’s general election. Laura Pidcock went on to win the seat for Labour.

Labour’s shadow equalities minister, Naz Shah, said: “This disgusting Islamophobia and homophobia have no place in our society. And no one who spreads these vile far-right conspiracy theories is fit to be an MP.

“Boris Johnson has claimed that Conservative members who do this sort of thing are ‘out first bounce’. So it defies belief that Sally-Ann Hart was selected as a candidate in the first place, and it is shameful that Boris Johnson is now failing to take action.”

The Guardian reported on Saturday how Hart was already being investigated for sharing a video in 2017 with an image suggesting that Jewish billionaire George Soros controls the EU. She also liked a comment left underneath the footage that said “Ein Reich”, which is a Nazi slogan.

Last week she was filmed at a hustings saying: “Some people with learning disabilities, they don’t understand about money. It’s about the happiness to work.”

In a separate development, a Tory activist who was suspended from the party for trying to make a “joke” about the New Zealand terror attack on Muslims has been allowed to return.

Martin Oddy, who wrote the words “shoe sale in New Zealand” on a Conservative Facebook group after 51 worshippers were murdered in March by a far-right activist in Christchurch, has returned to the Conservative party after completing an online diversity course.

A friend of Oddy said the businessman, who is a supporter of the Brexiter MP Andrea Jenkyns, maintained a right to tell jokes about any subject. “He is back in the party and back helping the Conservatives again,” the friend said.