In an unprecedented ruling, judges held by a 4-3 majority that Trump was necessarily disqualified by the 14th amendment to the US Constitution, which was introduced after the civil war and bans insurrectionists from electoral politics, though does not explicitly mention the presidency.

The former president’s actions leading up to and during the storming of the US Capitol on 6 January 2021, as legislators were preparing to formalise Biden’s victory, constituted “overt, voluntary and direct participation” in insurrection, the court said.

The 213-page judgment states: “We conclude that because President Trump is disqualified from holding the office of President under Section Three (of the 14th Amendment), it would be a wrongful act under the Election Code for the Secretary to list President Trump as a candidate on the presidential primary ballot.

“Therefore, the Secretary may not list President Trump’s name on the 2024 presidential primary ballot, nor may she count any write-in votes cast for him.”

The matter is certain to be appealed to the US Supreme Court, which legal analysts say currently has a conservative supermajority.

Trump’s lawyers will seek to have the issue appealed as swiftly as possible, as there is a 5 January 2024 deadline for Republican candidates to register for the Colorado primary elections.

Trump campaign spokesperson Steven Cheung said: “We have full confidence that the US Supreme Court will quickly rule in our favour and finally put an end to these un-American lawsuits.”