The United States Supreme Court has rejected a bid by the state of Missouri to halt Donald Trump’s upcoming sentencing for his conviction in New York on criminal charges involving hush money paid to a porn star.

The court also left a related gag order in place until after the November US presidential election, in which Trump is the Republican nominee.

The decision by the justices came in response to Missouri’s lawsuit claiming that the case against Trump infringed on the right of voters under the US Constitution to hear from the former president as he seeks to regain the White House.

The Supreme Court’s order was unsigned. Conservative Justices Clarence Thomas and Samuel Alito indicated they would have taken up Missouri’s case but added that they “would not grant other relief”.

Trump was found guilty in May of falsifying business records to cover up a US$130,000 ($217,000) payment to porn star Stormy Daniels in exchange for her silence before the 2016 US election about a sexual encounter she has said she had with Trump years earlier.

Prosecutors have said the payment was designed to help Trump’s chances in the 2016 election, where he defeated Democrat Hillary Clinton.

Trump denies having had sex with Daniels and has vowed to appeal his conviction after his sentencing, scheduled for September.

Missouri’s Republican Attorney-General Andrew Bailey filed a July 3 lawsuit against New York state asking the Supreme Court to pause Trump’s impending sentencing and the gag order placed on him by New York state judge Justice Juan Merchan.

Legal disputes between states are filed directly to the Supreme Court.

Bailey argued that the criminal case against Trump violated the right of Missouri residents under the Constitution’s First Amendment to “hear from and vote for their preferred presidential candidate”.

“Instead of letting presidential candidates campaign on their own merits, radical progressives in New York are trying to rig the 2024 election by waging a direct attack on our democratic process,” Bailey said.

Republican attorneys-general from Florida, Iowa, Montana, and Alaska filed a brief in support of Missouri’s lawsuit.

Trump also faces federal and state criminal charges involving his efforts to undo his 2020 election loss to President Joe Biden.

The Supreme Court in a July 1 ruling powered by its six-three conservative majority granted Trump substantial criminal immunity for actions taken in office. It all but ensured Trump would not face trial in the federal election subversion case before the election.

Trump’s lawyers promptly invoked the immunity ruling in a bid to toss out the hush money verdict.

They said prosecutors improperly relied on social media posts made in 2018 by Trump when he was serving as president that qualified as official communications.

The judge in the case said he would rule on Trump’s arguments by September 6. Merchan said that if he upholds the conviction, he would sentence Trump on September 18.

A New York state appeals court last week rejected Trump’s challenge to his gag order.

The decision by the Appellate Division in Manhattan means Trump, who has called all the criminal cases against him politically motivated, cannot comment publicly about individual prosecutors and others in the case until his sentencing.