Liz Kendall has offered support to Harriet Harman, after Labour's acting leader sparked an internal backlash for committing the party to supporting some of George Osborne's welfare cuts.
On Sunday, Harman said Labour would accept the overall household benefits cap and the chancellor's decision to limit support through tax credits and universal credits to two children. She is due to face Labour MPs this evening at what could be a difficult meeting of the Parliamentary Labour Party.
Kendall's three rivals for the Labour leadership, Yvette Cooper, Andy Burnham and Jeremy Corbyn have all strongly criticised Harman's position.
However Kendall told the BBC's Victoria Derbyshire programme today that Harman had been "absolutely right" to say Labour could not oppose the Conservative Budget measures without putting forward "a different credible alternate".
"I want to support what Harriet said, we have to listen to what people have said to us, that they didn’t trust us and we have to change as a party," she said.
"People said to us 'we don’t trust you on the money, we don’t trust you on welfare reform'. If we are going to oppose things we have to put something else in its place."
Asked whether she supported Conservative plans to limit child tax credits to the first two children, Kendall said: "Many parents who aren’t on tax credits have to make difficult decisions about how many kids they have and how many kids they can afford."
On Monday morning, Harman appeared to try and walk back her comments. A Labour source told the BBC that she had been setting out an "an attitude" not a final policy and would be happy for her support for cuts to tax credits to be overruled.
Harman has said Labour would oppose some of the changes to tax credits, which would hit low-paid workers despite the announcement of the new national living wage (NLW).
"Obviously we welcome the increase in what they're now calling the National Living Wage, but pointing out that there will be three million families who are working hard who are actually going to be £1,000 worse off. So we will oppose that.
"We will oppose too the abolition of the child poverty targets, but actually we're not going to do blanket opposition because we've heard all around the country that, whilst people have got concerns, particularly about the standard of living for low-income families in work, they don't want blanket opposition to what the Government are proposing on welfare."
Kendall also dismissed claims she was adopting Tory policies. "If you believe that a strong economy, sound public finances and backing businesses are simply Tory values, the Tories will be in power for ever," she said.
Campaign Chair Toby Perkins said: "In line with polling we have done and that held by national pollsters, the more the public see of Liz Kendall the clearer it is that she is the only one that offers Labour a fresh start with voters.
"This audience had her as the clear winner in a key marginal seat. The Labour Party will be left with a clear choice at this election between comfort and victory- I hope that they listen to the voters who have deserted us in recent elections- and choose victory, by backing Liz Kendall."