Along with other Hispanic education advocates, Ruben Cortez was pleased to discover that Texas might approve a Mexican American studies textbook for use in public schools.

Then he read it.

The textbook, Mexican American Heritage, is packed with “flagrant falsehoods and offensive racial stereotypes”, the state board of education member told a press conference on Tuesday in Brownsville, near the border with Mexico. “Frankly this sounds like something in line with what you’d hear in the Trump campaign.”

Cortez convened an eight-member committee of academics and teachers to examine the book, and they produced a 54-page report (pdf) which details what they say are 141 errors of fact, interpretation and omission.

“It is an utter shame that we as policymakers, educational professionals and communities across this great state must deal with this racially offensive and poor attempt at academic work,” Cortez said. “Clearly intended to be a political Trojan horse into our schools, this textbook is a complete disaster and this should not even be considered a textbook, rather a political manifesto aimed at distorting the perceptions of our most valuable resources, our children.”

The report’s authors accuse the book, by Jaime Riddle and Valarie Angle, of having a “primary thesis, that Mexican American history reveals major menacing or un-American trends in American history, society and culture”.

According to the book, Chicano activists “adopted a revolutionary narrative that opposed western civilization and wanted to destroy this society”. The report’s authors also take exception to a passage that states: “Illegal immigration has … caused a number of economic and security problems in the United States over which people are divided on how to solve. Poverty, non-assimilation, drugs, crime and exploitation are among some of these problems”.

Shortly afterwards, the report adds, the book claims that some people worry “that Spanish-speaking communities could, over time, become more connected to the world of Mexico rather than to the United States, threatening the stability of the country”.

The book repeats a view of Mexicans as indolent, then fails to challenge the falsehood, the report says. It quotes a passage: “Stereotypically, Mexicans were viewed as lazy compared to European or American workers. Industrialists were very driven, competitive men who were always on the clock and continually concerned about efficiency.

“They were used to their workers putting in a full day’s work, quietly and obediently, and respecting rules, authority and property. In contrast, Mexican laborers were not reared to put in a full day’s work so vigorously. There was a cultural attitude of ‘mañana,’ or ‘tomorrow’, when it came to high-gear production. It was also traditional to skip work on Mondays, and drinking on the job could be a problem.”

The publisher, Virginia-based Momentum Instruction, is run by Cynthia Dunbar, who served a four-year term on the state education board and wrote a book in 2008, One Nation Under God, subtitled How the Left is Trying to Erase What Made Us Great, which described public education as a “subtly deceptive tool of perversion”.

Dunbar said that the part about “lazy” Mexicans had been misinterpreted by the book’s detractors. “That was a racial bias and stereotype that was being put forward by industrialists and the book was exposing that, that was something that they were having to confront and overcome,” she told the Guardian.

“There’s no hidden agenda in the textbook, there’s no bias, there’s no stigma that’s trying to be put forward, we’re trying to work with as many people as possible to make sure that if there’s any language that’s confusing, or could be edited, that we do that. But for some reason these people are more concerned with doing press conferences than they are with actually submitting statements of objective factual errors to us to correct. There’s no racial bias in the textbook, I don’t know why they keep twisting it to try to put it forward.”

She said that only one factual error has been noted by a state review panel – a sentence that seemed to imply that the US’s official language is English, when the country has no official language – and that that the authors were well qualified to research and write a wide-ranging book on the subject.

Cortez, a Democrat, said that just over half of the roughly five million children in Texas public schools are Hispanic. The board of education will hold a public hearing next Tuesday before deciding whether to adopt the textbook in November.

The production and adoption of Texas textbooks has long been freighted with political and cultural controversies that have intensified in recent years as the 15-strong board has become dominated by conservatives who, critics say, have sought to promote their rightwing views on topics such as religion, climate change, capitalism and America’s creation.

In 2015, after an outcry promoted by a Houston-area mother’s online critique, a publisher revised a passage in a geography book that described African slaves brought to the US as immigrant “workers”.

Earlier this year, Mary Lou Bruner – who asserted that the twentysomething Barack Obama was a drug-taking male prostitute, pre-kindergarten programmes are a federal plot to promote gay marriage and the Democratic party killed John F Kennedy – almost won the Republican nomination for one of the seats on the board.