Former US President Donald Trump has been indicted in connection with the events surrounding the 6 January 2021 riots at the US Capitol.

The Republican politician denies wrongdoing and has described the case as “ridiculous”.

He has already been charged in two other cases – with mishandling classified files and falsifying business records to cover up a hush-money payment to a porn star.

Here are some of the key questions surrounding the case.

What are the charges?

Mr Trump, who lost the 2020 presidential election to Democrat Joe Biden, has been charged with plotting to overturn his defeat.

He is accused of four counts:

• conspiracy to defraud the US
• conspiracy to obstruct an official proceeding
• obstruction of an official proceeding
• conspiracy against the rights of citizens

These charges relate to Mr Trump’s actions over a period of more than two months from soon after election day (3 November) until the day he left the White House on 20 January.

The first count refers to alleged attempts to obstruct the collection, counting and certification of votes.

The second and third deal with alleged attempts to obstruct the certification of electoral college votes in the US Congress on 6 January, which culminated in the Capitol riots.

The fourth charge is about alleged attempts to interfere with citizens’ right to vote and to have their votes counted.

How serious are the charges compared to previous indictments?

This is Mr Trump’s third indictment and some legal experts have said it may not be the strongest case brought against him. He may face deeper legal peril elsewhere.

But in terms of the gravity of the charges, these are the most serious and consequential, says our North America editor, Sarah Smith.

This is the first time he is being indicted for something which took place while he was still in office, she says. And there is also a real-world impact laid out in this indictment which we have not seen in the other cases.

Although special counsel Jack Smith stopped short of charging Mr Trump with inciting the mob which attacked the US Capitol, the prosecutor said it was “fuelled by lies, lies by the defendant”.

Former federal prosecutor Renato Mariotti told the BBC’s Today programme that this was the first indictment in US history that was charging a former president for conduct that was unique to his office, in other words “trying to remain in office and prevent the peaceful transfer to power”.

What happens next?

Mr Trump is due to appear in court in Washington DC on Thursday. It is not clear as yet whether he will appear in person or remotely.

The man leading the inquiry, special counsel Jack Smith, is pledging to seek a “speed

This trial will be competing for time with the other cases against him – they cannot all be conducted at the same time. Also it is unlikely to be scheduled for key moments during the election, such as the Republican National Convention when a presidential candidate is formally chosen.