Senators have called for an inquiry over Angus Taylor’s “clear breaches” of ministerial standards.

Mr Taylor “consciously used his position as an MP and minister” to influence an investigation into clearing of grasslands at a property he and his family part-own, according to a new Senate committee report.

Mr Taylor, when he was the assistant minister for cities, asked for briefings on the listing protections for critically endangered natural temperate grassland of the south-eastern NSW highlands.

Mr Taylor’s family are major landholders on the Monaro plains, where the majority of these ecological communities are located.

A company in which Mr Taylor and his family had interests has been investigated by the federal environment department for poisoning grasslands at Corrowong.

The company, Jam Land, faces potential fines of more than $10 million. Mr Taylor has a shareholding through his family company Gufee and his brother Richard is a director.

Mr Taylor received briefings from the environment department on the grasslands protections in March 2017.

Mr Frydenberg, the then environment minister, sought advice on whether protections for the grasslands could be weakened without making such a decision public.

The Labor-Greens dominated committee wants the Department of the Prime Minister and Cabinet to investigate the Mr Taylor and treasurer Josh Frydenberg’s handling of the grasslands saga.

“It is inconceivable that Mr Taylor was unaware that he and his family stood to benefit directly from his actions,” the interim report of the Senate’s faunal extinctions inquiry states.

The committee considered evidence from the department, as well as email correspondence between the department and Frydenberg’s office.

“In considering the evidence, the committee has reached the conclusion that Mr Taylor consciously used his position as an MP and minister to make representations to minister Frydenberg that were aimed at affecting the outcome of the Jam Land compliance case,” the committee states.

“In doing so, Mr Taylor repeatedly failed to disclose his family and personal financial interests in Jam Land in an appropriate and transparent manner, not only to minister Frydenberg and his department but also the parliament.”

The report also noted that Mr Frydenberg did not declare Mr Taylor’s interest in Jam Land to his department.

“Evidence indicates that Mr Taylor did not only fail to disclose his vested interests, but also sought to use his ministerial office and parliamentary connections to obtain special treatment for himself and his family, which is not offered to any other landholder in Australia,” the report states.

Coalition senators on the committee issued a dissenting report that labelled the recommendations blatantly partisan.

“The evidence provided by the department confirms that Mr Taylor has acted appropriately and in accordance with the rules. Labor and Greens senators continuing to repeat claims and assertions for partisan political reasons do not change this fact,” it said.

“Coalition senators deplore this inappropriate misuse of a Senate committee with a valid environmental terms of reference to be subverted for partisan political purposes.”