Tens of thousands of the 1.5m households who have have started claims for universal credit during the last few weeks of the coronavirus crisis will lose out on vital financial support due to benefit restrictions on larger families, say campaigners. The DWP revealed on Tuesday the bulk of the 1.5m “declarations” – the term used to describe the start of a new claims for universal credit – came after mid-March when social distancing measures were introduced, with more than 100,000 claims arriving each day in the fortnight after lockdown was announced on 23 March. The work and pensions secretary, Thérèse Coffey, said the figures showed universal credit was providing vital support for all those who needed it. She praised the system for standing firm “in the face of the unprecedented demand” and paid tribute to staff for working overtime to help process the glut of new claims. However, a letter to the Guardian by 50 anti-poverty campaigners said that tens of thousands of families forced to sign on to universal credit in the last few weeks would discover they would receive no support for any third and subsequent children born since April 2017 because of the two-child limit on benefits. The letter, whose signatories include the Bishop of Durham, Oxfam, the Child Poverty Action Group and Christian, Muslim and Jewish groups, said: “Families newly affected by the two-child limit are being left with too little to meet their needs in circumstances entirely beyond their control. That is not right. The policy should be lifted before struggle turns to real hardship for the many affected families.” The limit, introduced in April 2017, restricts the child element in universal credit and tax credits worth £2,780 per child per year to the first two children, denying at least £53 a week benefit support for affected families. The government said it was an incentive for households to work, which also cut the benefits bill by £1bn a year. The letter, which also calls for the benefit cap to be scrapped, says: “The government’s rationale for the policy is that parents claiming universal credit or tax credits should face the same choices about the number of children they can afford as those supporting themselves solely through work. But the current national crisis has exposed that argument as untenable. “Even in normal times, no parent can be sure that their financial security will withstand unpredictable events such as illness, bereavement or redundancy. Certainly no parent could have had foresight of Covid-19 and so planned their family size accordingly.” About 93% of the new claims would be paid on time, the DWP said, after claimants had gone through the standard five-week wait. The first batch of payments to the cohort of “pandemic claimants” is expected on Wednesday. However, the DWP was unable to say how many applicants had been refused universal credit, which is a means-tested benefit. Households where one adult is still working, or where the level of savings is more than £16,000, or where the claimants received a final pay cheque, may not immediately qualify for the benefit. More than 500,000 of the new claimants took out advance loans from the DWP to tide them over the five-week payment waiting time. These loans must be repaid from subsequent monthly benefit payments at a rate of up to 25% of the standard allowance, leading to criticism that they can push vulnerable people into debt. The Labour party this week called for the five week waiting time to be scrapped, and for advance loans to be written off as grants as part of a raft of policy changes to increase the level of financial support for families forced to rely on universal credit and tackle rising poverty. Roughly a third of the new universal credit claimants took out advance loans in March and April, a smaller proportion than the 60% that normally take up out universal advance loans, suggesting that many of the latest cohort of claimants either were unaware of advances or had sufficient savings to tide them over the five-week wait.