Boris Johnson warned of “tough times ahead” as the nation emerges from the coronavirus lockdown, and sought to blame Labour for the failure to get more pupils back in school.

Against a backdrop of mounting evidence about the economic cost of the shutdown, the Prime Minister said the Government had done “everything we possibly can” to help families in need, and is ready to go further “where we can”.

After abandoning an effort to get all England’s primary schools back in class before the summer, the Conservatives mounted an attack on Opposition leader Sir Keir Starmer over the issue, with Mr Johnson repeatedly challenging him to agree that it was safe for children to return.

We are fully aware that there will be tough times ahead and we do stand by to do more where we ca

Culture Secretary Oliver Dowden used the daily Downing Street coronavirus press conference to step up the attempt to blame Labour and the education unions for the failure to get more children in class.

At Prime Minister’s Questions, Mr Johnson accused the Opposition of “wibble-wobble” over the issue, insisting “the kids that can go to school should go to school”.

Mr Dowden said it was important to “reassure parents that it is safe for their kids to go back”.

“I do think it’s a bit of a shame that their unions, and indeed it appears the leader of the Labour Party, is not also providing them with that kind of backing and support.”

Sir Keir’s spokesman said: “Ultimately it was (Education Secretary) Gavin Williamson who said on June 9 we’re not able to welcome all primary children back for a full month before the summer.

“That was a Government U-turn, that was a Government failure and this is a Government with the majority of 80, it should be taking the responsibility for its own failures.”

In other developments:

– England and Manchester United star Marcus Rashford said he is planning his next move to help struggling families after his successful campaign to extend the children’s food voucher scheme into the summer holidays.

– The NHS contact tracing app, announced with a fanfare when initial trials began on the Isle of Wight in early May, might not be ready until winter and “isn’t the priority”, health minister Lord Bethell told MPs.

– Health Secretary Matt Hancock apologised after being caught on camera breaking social distancing rules by patting a colleague on the back in the House of Commons.

– Mr Hancock said an announcement on updated advice for the 2.2 million people in England who are currently shielding will be made “very soon”.

– Health Education England (HEE) denied it is cutting pay for student nurses working on the front line against Covid-19 as some claimed they faced hardship after being told paid placements will now finish at the end of July instead of running until September.

– Mr Dowden pleaded with football fans to stay at home to watch games as the Premier League resumed behind closed doors after the lockdown.

The row over schools came as a survey indicated the pressures faced by families as a result of the lockdown.

Research suggested around two thirds of households receiving Universal Credit have been forced into debt during the coronavirus lockdown.

The Joseph Rowntree Foundation (JRF) and Save the Children surveyed 3,105 parents of children under 18 claiming either Universal Credit or Child Tax Credit during late May and early June.

It found that 60% of families receiving the benefits had turned to payday loans or using credit cards to borrow money.

Save the Children and the JRF are arguing for a £20-per-week increase to the child element of Universal Credit and Child Tax Credit to minimise the impact of the coronavirus crisis on youngsters.

Mr Johnson said: “This is a Government that has done everything we possibly can so far to help families in need, to make sure that nobody is penalised for doing the right thing during the crisis, because I know how difficult it has been.”

The Government has already injected £6.5 billion into the welfare system, including increasing Universal Credit and Working Tax Credit by up to £1,040 a year.

In response to questions from the SNP’s Westminster leader Ian Blackford, Mr Johnson said: “We are fully aware that there will be tough times ahead and we do stand by to do more where we can.”

Official figures in recent days have highlighted the economic cost of the coronavirus lockdown.

Statistics released on Tuesday showed a sharp drop in the number of paid employees – down by 2.1% or 612,000 in May compared with March – and a huge increase in benefit claims.

Data published last week revealed that the UK’s economy shrank by 20.4% in April – the largest monthly contraction on record – as the country spent its first full month in lockdown.