WASHINGTON, United States: The US Supreme Court dealt a major blow Monday to President Donald Trump’s attempts to restrict mail-in voting before the November midterm elections, denying his request to lift an order halting the divisive plan.

Only two of the six conservative justices on the nine-member panel offered a dissent.

Justice Brett Kavanaugh, in a concurring opinion with the majority, said Trump’s plan may ultimately be legal in the long run, but “state and local election officials do not have sufficient time to reasonably implement the rule before the elections.”

Trump signed an executive order in March seeking to restrict mail-in voting, saying without evidence that it is vulnerable to fraud. The order quickly prompted multiple legal challenges.

Democratic-led states sued the administration on grounds that under the US Constitution, states — and not the federal government — retain broad control over the administration of elections.

Trump’s executive order would require the compilation of lists of eligible voters and for the US Postal Service (USPS) to deliver ballots only to voters who are on the lists.

Officials from several states had warned that a lack of legal clarity around the plan was sowing chaos months before the November 3 vote.

Several states, including North Carolina, have already begun sending mail-in ballots to voters.

A USPS whistleblower had also warned that millions of Americans may not receive ballots because the systems being used by the postal service have been put together in a “sloppy and rushed manner.”

Trump has long been a critic of mail-in ballots but has frequently used them himself, including last month when he voted by mail in Florida’s Republican primary.

The president has for years claimed without evidence that mail-in voting is highly vulnerable to fraud, repeatedly linking it to his false assertion that the 2020 presidential election was stolen from him by Democrat Joe Biden.

Polls show that Trump’s Republican Party faces a serious threat of losing its narrow control of Congress in November, particularly the House of Representatives.

If Democrats win, they have signaled they would block Trump’s agenda and could even move to impeach him for the third time.