The Republican party in Texas has officially adopted a series of extreme-right positions that includes claims Joe Biden was not legitimately elected and homosexuality is “abnormal”.

In a platform adopted at its biennial convention in Houston, delegates voted to oppose “all efforts to validate transgender identity”, including the use of taxpayer funds for any “medical gender dysphoria treatments or sex change operations”.

The anti-trans and anti-gay declarations are part of the state party’s new guiding principles, in a section titled homosexuality and gender issues, which contradict claims by some Republicans that the GOP wants to be more inclusive.

Adopted planks include opposition to giving a special legal status to gay men or women, while supporting those who oppose homosexuality based on faith, religion or a belief in “traditional values”. Military personnel, prison inmates and young people struggling with body dysmorphia and gender identity issues are singled out as groups who should not receive care and treatment.

The state party’s stance is a rebuke to Biden’s recent executive order designed to protect the LGBTQ+ community from a wave of state laws in Republican states such as Texas that prevent access to health care resources and ban the discussion of sexual orientation and gender identity in schools.

In another section dedicated to education, the platform calls for students in Texas to “learn about the humanity of the preborn child”, by witnessing a live ultrasound and the use of fetal baby models. The supreme court decision on abortion access is expected in the coming days, but Texas has already criminalized abortion in most cases.

The resolution embracing falsehoods about the 2020 election stated that “substantial election fraud in key metropolitan areas significantly affected the results in five key states in favor of … Biden.” The state party rejects “the certified results of the 2020 presidential election, and we hold that acting President Joseph Robinette Biden Jr was not legitimately elected by the people of the United States.”

The resolution encouraged Republicans to “show up to vote” in the November midterms, and to “bring your friends and family, volunteer for your local Republicans and overwhelm any possible fraud”.

The state party also supports further restriction on mail-in voting and for the Voting Rights Act of 1965, the landmark legislation which outlawed racial discrimination in elections, to be “repealed and not reauthorized”.

Overall, the new platform provides more evidence of Texas Republicans moving further to the extreme right. Republicans, who control the legislature, governor’s mansion and every statewide office, have used their dominance to push through a swath of regressive laws in recent months including anti-abortion, anti-LGBTQ+, anti-migrant and anti-voting rights legislation.

Steve Toth, the state representative for part of Montgomery county, a Houston suburb, denied the party was moving to the right. “Defense of marriage? Abortion? Second amendment? Where have we moved to the right?… The Republicans have always been strong defenders of constitutional family values.”