Former President Donald Trump has launched a scathing personal attack on fellow Republican Mitch McConnell.

"Mitch is a dour, sullen, and unsmiling political hack," said Mr Trump, "and if Republican Senators are going to stay with him, they will not win again."

Mr McConnell, who led the Senate for years, voted to acquit Mr Trump in his impeachment trial last week.

But he then attacked him as "morally responsible" for the US Capitol riot because of his election fraud "lies".

In a speech on the Senate floor, he implied Mr Trump should face criminal and civil litigation, because he was "still liable for everything he did while in office".

What did Trump say about McConnell?

Mr Trump responded on Tuesday with his lengthiest statement since he left office a month ago.

"The Republican Party can never again be respected or strong with political 'leaders' like Senator Mitch McConnell at its helm," the press release reads.

Mr McConnell's "lack of political insight, wisdom, skill, and personality" had cost the Republicans control of the Senate following last November's elections, he said.

The former president said the Republican leader "begged" for his endorsement in his own Senate race, without which Mr Trump claimed Mr McConnell would have lost.

Mr Trump took aim at Mr McConnell's stated intentions to stand in the way of future Trump-backed candidates.

The former president said he would back Republican primary challengers who "espouse Making America Great Again and our policy of America First".

Mr McConnell "will never do what needs to be done, or what is right for our Country," said Mr Trump.

"We know our America First agenda is a winner, not McConnell's Beltway First agenda or Biden's America Last."