Liz Truss has accepted help during her leadership campaign from a former government minister accused of sexual harassment, sources claim No 10.

The prime minister was not only aware of the allegations, officials said, but suggested he could return to serve in his government.

The politician, who denies any wrongdoing, first tried to settle the matter informally with a letter of apology to the woman before reaching a financial settlement this summer.

A second official also claimed the minister, who was part of Boris Johnson’s government, made harassing comments to him, which he also denies.

Allegations of his links to Ms Truss come at the end of a tough Tory conference for the Prime Minister and put further pressure on his refusal to appoint a parliamentary ethics adviser after Mr Johnson quit the role earlier this year .

She has rejected calls to do so, saying during her campaign that she knows the “difference between right and wrong”.

The Independent understands the former minister provided some behind-the-scenes support for the Truss leadership campaign while she was aware of the allegations, according to two No 10 officials.

She was among a group of cabinet members, including Mr Johnson, who were informally briefed on the allegations, sources said. No official investigation has been carried out.

The former minister allegedly made inappropriate comments to the official, who later filed a complaint. Senior officials reviewed the comments and decided an investigation was not warranted.

The alleged victim was unable to turn to the Independent Complaints and Grievances Scheme (ICGS), which deals with incidents on Parliamentary grounds – but not in Whitehall or beyond. Civil servants can only access the ICGS if an incident has occurred on the estate and it involves a member of the parliamentary community.

After his efforts to get an investigation proved unsuccessful, the alleged victim threatened to sue the former minister.

The out-of-court financial settlement did not include an admission of wrongdoing by the ex-minister, it is understood.

A second official, who had worked with the former minister, said The Independent they were aware of the allegations and had also been the subject of inappropriate remarks.

She said “it was important for people to understand that this is not an isolated case” regarding his alleged behavior.

Number 10 declined to comment last night, saying the matter was about Ms Truss’ leadership bid. Spokespersons for Ms. Truss did not respond to a request for comment.

Concerns about inappropriate behavior have swirled around Westminster during Mr Johnson’s tenure amid fears it will go unchecked.

The handling of allegations involving MP Chris Pincher, the former minister accused of groping young men at a private club, was the final straw in the former prime minister’s prolonged downfall.

Rejecting calls for an ethics counsellor, Ms Truss said during a Conservative leadership campaign in August that she would ‘make sure the right apparatus is in place so people can speak out’ – but bosses Unions fear that, without a figurehead, it will be “difficult” for victims of misconduct, especially civil servants, to seek justice.

Mark Serwotka, general secretary of the Public and Commercial Services Union (PCS), which represents thousands of civil servants, said: ‘By choosing not to appoint an independent ethics adviser, Liz Truss appears to be showing the same disregard for of ministerial misconduct than his predecessor. .”

A PCS spokesman added that there was a ‘lack of will’ under Mr Johnson’s administration to investigate allegations of ministerial misconduct, ‘making it difficult for victims to speak out and s ensure that disciplinary action has been taken”.

Last week, the ICGS dropped a complaint against Mr Pincher because the incident did not occur in the parliamentary realm. At least one of the alleged victims has lodged an appeal with the Parliament’s Commissioner for Standards, according to reports.

Sources in various roles at Westminster said there are often few effective remedies for alleged victims. One said there was often “a choice between speaking out and pushing to get something done, or clinging to your career”. Others warned of a culture of cover-up when it comes to ministerial misconduct.

The Parliamentary Commissioner for Standards has said he ‘has no power to investigate complaints about the manner in which government ministers carry out their ministerial responsibilities’.

Labour’s Jess Phillips, who has pushed for greater transparency in the handling of complaints in Whitehall, said there was “a clear gap in the systems for civil servants working with ministers”.