Michael Flynn, a longtime adviser to Donald Trump, has sued the congressional committee investigating the deadly 6 January attack on the US Capitol in hopes of blocking it from obtaining his phone records.

Flynn alleged in a lawsuit, filed in federal court in Florida, that a subpoena issued to him by the House of Representatives select committee was too broad in scope and punishes him for constitutionally protected speech as a private citizen.

Flynn also alleged in the lawsuit that the committee “has no authority to conduct business because it is not a duly constituted select committee”.

An appeals court has rejected that argument, ruling on 9 December that the committee was valid and entitled to see White House records Trump has tried to shield.

The committee issued a subpoena to Flynn, Trump’s short-lived former national security adviser, in November, seeking testimony and documents about a “command center” at Washington’s Willard Hotel set up to steer efforts to deny Joe Biden his November 2020 election victory.

After the election Flynn urged Trump to deploy the military to overturn the results and gave speeches sowing doubts about the vote.

The select committee did not comment.

Flynn’s lawsuit is the latest in a flood of litigation by targets of the committee, seeking to prevent it from enforcing its subpoenas.

Alex Jones, the conspiracy theorist and founder of the rightwing website Infowars, filed a similar case on Monday.

Trump has similarly sought to block the committee from obtaining his White House records from 6 January and the preceding days, asserting they are protected by a legal doctrine called executive privilege. An appeals court rejected Trump’s arguments last week. He is expected to appeal to the supreme court.

Flynn was previously charged as part of former special counsel Robert Mueller’s investigation into Russian influence on the 2016 presidential election won by Trump.

Flynn, a retired Army general, pleaded guilty to lying to the FBI about interactions he had with Russia’s ambassador to the US in January 2017. Trump later pardoned him.