Labour leader Jeremy Corbyn has told a well-wisher that "we are not far off, are we" in the wake of general election results that saw the party make gains.
Mr Corbyn made the comment after a supporter shook his hand in the street and said: "Unlucky."
But one of his critics, former shadow chancellor Chris Leslie, said the result was "not good enough" and should not be seen as a "famous victory".
Labour gained 30 seats in the election, enough to prevent a Tory majority.
Mr Corbyn seemed to be in good spirits on Saturday as he walked with a posse of media from his house to a nearby meeting, later posing with Times columnist Giles Coren for a selfie at a children's football session.
Conservative leader Theresa May was not seen on Saturday, as talks continued about forming a government with the support of the DUP.
Mr Leslie told BBC Radio 4's Today programme about Labour's performance: "We shouldn't pretend that this is a famous victory. It's good as far as it's gone, but it's not going to be good enough."
Labour secured 262 seats in the election and boosted its vote share to 40%.
The Conservatives won 318 seats - eight fewer than they needed in order to secure a majority.
Mr Leslie said Labour missed an "open goal" as he had "never known" a more beatable prime minister than Theresa May.
The Labour MP for Nottingham East refused to say whether he thought Mr Corbyn was a credible prime minister.
"I will never apologise for my view which is, yes of course you've got to inspire people, and we haven't done that well enough in the past.
"But you've got to convince them of your credibility and that you can move from protesting about the government to being in government."
Mr Leslie said Labour MPs were "working in this together" but he would not commit to serving in a shadow cabinet.
He said he feared an issue would arise that would go against his principles and he would have to resign.
"I'm never going to give in arguing for what I believe is a pathway to a majority Labour government," he added.
However, shadow defence secretary Nia Griffith has called on Theresa May to step aside to allow Labour a chance to form a minority government.
She told BBC Radio Wales: "We're still saying quite clearly that we would be ready to take over if Theresa May cannot cobble something together, and we're very doubtful that she can.
"We don't really think she has a mandate to now, she's really made a fool of herself and really, quite frankly, she should step aside and let us have a go."
Mr Corbyn had given the party "confidence" about selling party policies such as public ownership of the railways, she added.