Sir Keir Starmer has claimed the "vast majority" of Labour members are behind him and his team, despite criticism from the left of the party.
HuffPost has reported some figures are calling for an emergency conference because of "anger and disillusionment" at the direction Sir Keir is taking.
But the Labour leader said he was "focusing on the right things" during the pandemic and the party backed him.
Sir Keir has led Labour for 10 months since taking over from Jeremy Corbyn.
His leadership win followed the party's worst general election defeat since 1935, with Labour's vote share falling by eight points and it losing many of its heartland seats.
But Mr Corbyn's allies within the left wing of the party have cast doubt of Sir Keir's plans - along with the Unite union and grassroots organisation Momentum, who are joining the Socialist Campaign Group of Labour MPs in their call for the emergency conference.
Labour MP Richard Burgon said: "Many feel our leadership has taken the fight to its own members more than it has to a Tory government responsible for one of the worst coronavirus death rates in the world."
Sir Keir was asked about divisions in the party on a visit to Essex, where he was calling for a six month extension to business rate relief and VAT cuts for certain sectors.
He said: "I don't think that's right - the vast majority of party and movement are behind what we're doing.
"They know we're in middle of pandemic. Most are saying: 'let's get vaccine rolled out, make sure this is the last lockdown and get back to degree of normality'.
"They are also saying we can't go back to business as usual because the pandemic has brutally exposed the inequalities in the system - we need to build a better future."
Twelve months since the voters of Islington North Labour put their crosses narrowly in Sir Keir's box, there are at least the beginnings of grumblings about his leadership.
He made a mistake in Prime Minister's Questions last week, reportedly losing his cool with Boris Johnson afterwards.
And there have been criticisms on the left of the party too - with one MP last week accusing Sir Keir in a national newspaper column of advocating "phoney flag waving", in the absence of "little vision and even less analysis" of why the country is in the position it is.
But the Corbyn project, with all its associated fighting between the different wings of the parties, prompted such a rupture, that Sir Keir's team has to - as they see it - clean up a mess first, to then start again.
There are grumbles. There are questions. But, this does not feel like a moment of genuine danger for Sir Keir's leadership.
He has changed so much about the Labour Party in 12 months, and certainly, is on the journey to make the party again, a credible opposition.
But as he knows, that will not always be enough.
Sir Keir accepted that being leader was "challenging all the time" because Labour had a "mountain to climb" before the next election in 2024.
But he insisted Labour under his leadership was "focusing on the right things [and] making the right challenges", such as over Universal Credit, cladding and supporting businesses, adding: "Our priorities are in the right place - businesses and families coming out of pandemic."
Asked about polling over the party's performance, Sir Keir said Labour were taking a "step in right direction" from its election defeat in 2019.
But, he added, there was "a long way to go between now and 2024", and the party was "working hard every day".