People should take up zero-hour contracts to avoid having their benefits docked, the work and pensions secretary has said.

Amber Rudd, who was appointed to the role last month, said benefit claimants should accept insecure jobs or risk having their payments reduced, prompting anger from MPs who said the warning could push people into exploitative work such as prostitution.

During a wide-ranging discussion with the Work and Pensions Committee, Ms Rudd admitted she had “concerns” about a number of aspects of the current welfare system, including the two-child limit, disability assessments and universal credit delays.

She was even commended by committee chair Frank Field for “not bulls***ting” after she told MPs she had not yet been able to secure support from her Conservative colleagues about her plans for the universal credit roll out.

“It’s so helpful for not just parliament but for the public when ministers give an answer like that – who don’t bulls***t. We now know where we are on that. You haven’t got agreement, you’re seeking agreement,” Mr Field said.

But the work and pensions secretary provoked anger with her assertions about benefit sanctions, a controversial measure that docks benefits as a punishment for alleged failures to comply with Jobcentre Plus rules, such as accepting work.

Committee member Chris Stephens, of the Scottish National Party, questioned Ms Rudd on the sanctions placed on people under universal credit if they refuse a zero-hour contract job, to which she replied: “But people should go into work. The principle of sanctions is there’s conditionality.”

Mr Stephens then asked the secretary of state to confirm that she meant people should take zero-hour contracts or “insecure work”, to which Ms Rudd said: “Well I would say yes, if people are offered work, they should take it.”

Labour MP Neil Coyle then intervened, saying: “If it’s prostitution? Because that’s the reality for some of the people directly affected. We’ve had that example here.”

A visibly angered Ms Rudd retorted: “We’ve had this conversation. If we’re talking about zero-hour contracts, do not bring up prostitution […] The fact is universal credit is designed to help people.

“For some people, zero-hour contracts work well […] The point about universal credit is you can earn money, it can be taxed in an appropriate way so you can still receive your benefits.”

Discussing universal credit more broadly, the work and pensions secretary admitted there were problems with the new system, and that the government “sometimes is not as good as it should be at rolling out hugely ambitious new changes”.

She continued: “It is changing, but we are only at the foothills in some respects, so I’m cautious about saying it’s coping well enough to be absolutely clear about how successful it’s going to be in the next few years.”

She also implied there may be further delays to the roll out of the welfare reform, saying: “It’s right to have goals, but I will be on top of making sure problems don’t emerge that we don’t address, and if we need to, slow down.”

On the two-child limit, a policy that restricts the payment of tax credits and universal credit to the first two children in a family and is currently being challenged in court, Ms Rudd accepted concerns but claimed she may not be able to make changes to it.

“I do support the policy that people need to consider when they’re having a third child their income as people in work do, but I do share your concerns about the retrospective element,” she said.