'Challenge me at the convention, Biden tells concerned Democrats

Joe Biden told Democrats questioning his leadership to "challenge me at the convention" yesterday and sent a combative letter to Congress defending his embattled candidacy, as Washington braced for what may be one of the most politically significant weeks in recent memory.

- Robert Tait, Chris Stein

The US president launched a counteroffensive as Congress prepared to reconvene after a two-week break, with leading Democrats facing pressure to reveal whether they plan to stick with him as their nominee.

Biden gave a surprise live interview to MSNBC's Morning Joe to bolster his letter to returning congressional Democrats, delivering the unambiguous message that he intended to fight on.

He pledged not to back down even as pressure continued to mount after some prominent House Democrats reportedly told the House minority leader, Hakeem Jeffries, in a virtual meeting that they believed the president should step aside in the race after his poor debate performance against Donald Trump and an underwhelming ABC interview.

"Challenge me at the convention," Biden told the show's co-hosts, Joe Scarborough and Mika Brzezinski, adding that the calls to step down had irked him.

"I'm getting so frustrated by the elites. I'm not talking about you guys, but about the elite in the party." The defiant posture came as the US Senate and House of Representatives prepared to enter session concurrently for the first time since the 27 June debate, during which Biden struggled to make his points, became muddled and could not effectively parry a litany of attacks and lies from Trump.

This drew renewed scrutiny to Biden's ability to serve as president for another four years as, at 81, he is already the oldest president in US history and had been suffering in the polls over questions over his mental fitness and stamina.

In his letter to Congress, Biden acknowledged these concerns but stressed that they had not weakened his resolve.