Jeremy Corbyn has reaffirmed his desire to scrap the welfare cap after differences with his shadow cabinet, calling the policy "devastating".
The Labour leader told the New Statesman his party opposed government plans to lower the overall household cap, introduced in the last Parliament.
And his spokesman confirmed he was "very much in favour" of getting rid of it altogether.
The Conservatives said Labour wanted a return to "unlimited welfare handouts".
The BBC's Carole Walker said Mr Corbyn was asserting his authority on what was a "very difficult issue" for the party.
After Mr Corbyn told the TUC conference last week he wanted to "remove the whole idea of the benefit cap", Owen Smith, his shadow work and pensions secretary, said it was "very clear" Labour was only opposing plans to reduce the limit of working-age benefits to £20,000, and to £23,000 in London.
In an interview with the BBC's Newsnight, Mr Smith acknowledged the principle of a welfare cap had wide public support and it would be "foolhardy" for Labour to set themselves "unthinkingly" against public opinion.
But Mr Corbyn told the New Statesman the cap was responsible for "social cleansing" in his Islington North constituency, with people forced to leave their homes because they could not afford their rent.
"It's devastating for children, devastating for the family and very bad for the community as a whole," he added.
His spokesman said Mr Corbyn had "laid out his position" and the policy would now go through a "collective decision-making process".
Speaking on Wednesday, Mr Smith said the party leader had "clearly signalled that he wants Labour to review and refresh our thinking on social security, especially in respect of the benefit cap, and that's a challenge I know the entire party will rise to in the months ahead".
Before Mr Corbyn was elected leader, the party was split over the Welfare Reform and Work Bill, which will reduce the cap to £20,000 outside of London, and £23,000 in London.
In July, 48 Labour MPs rebelled against the decision by the then interim leader Harriet Harman to abstain and instead voted against the bill.
'Chaos and confusion'
The Conservative Work and Pensions Secretary Iain Duncan Smith said "chaos and confusion" surrounded Labour's position.
"Conservatives believe that nobody should be able to claim more in welfare than the average family earns by going out to work," he said.
"By pledging to reverse this position, it's clear that today's Labour Party are simply not on the side of working people. They are still the same old welfare party - wanting to borrow more to spend more on benefits."
In his interview, Mr Corbyn also said scrapping the Trident nuclear weapons system would become Labour Party policy if its conference votes for the change next week.
Conferences votes are not technically binding on the party leadership.
But asked whether scrapping Trident would become party policy if conference votes for it, Mr Corbyn said: "Well, it would be, of course, because it would have been passed at conference."