Joe Biden’s position among congressional Democrats eroded further on Monday when an influential House committee member lent his voice to calls for him to end his presidential campaign following last month’s spectacular debate failure, the Guardian reported.

Adam Smith, the ranking Democrat on the armed services committee in the House of Representatives, issued the plea just hours after the president emphatically rejected calls for him to step aside in a letter to the party’s congressional contingent.

Biden had also expressed determination to continue in an unscheduled phone interview with the MSNBC politics show Morning Joe.

But in a clear sign such messaging may be falling on deaf ears, Smith suggested that sentiments of voters that he was too old to be an effective candidate and then president for the next four years was clear from opinion polls.

“The president’s performance in the debate was alarming to watch and the American people have made it clear they no longer see him as a credible candidate to serve four more years as president,” Smith, a congressman from Washington state, said in a statement.

“Since the debate, the president has not seriously addressed these concerns.”

He said the president should stand aside “as soon as possible”, though he qualified it by saying he would support him “unreservedly” if he insisted on remaining as the nominee.

Smith joins the ranks of five Democratic members of Congress who publicly demanded Biden’s withdrawal last week. He was among at least four others who spoke in favor of it privately in a virtual meeting on Sunday with Hakeem Jeffries, the party’s leader in the House.