Boris Johnson insisted he has a plan to “get our country back on its feet” amid warnings the UK is on course to suffer the biggest economic hit of any developed country from the coronavirus.

At Prime Minister’s questions, Mr Johnson promised extra cash to support vulnerable families and said the Government had “put its arms around the people of this country throughout this crisis”.

But he faced continued pressure about the failure to deliver on a goal of fully reopening England’s primary schools by the summer and there was further uncertainty about the introduction of an app as part of the Government’s test and trace programme.

In the Commons, where Mr Johnson faced questions about race relations in the UK following the protests triggered by the death of George Floyd, the Prime Minister said black and minority ethnic (Bame) workers had been at the forefront of efforts to tackle coronavirus in frontline jobs.

In response to a Public Health England report which laid bare the increased risk faced by ethnic minority groups, Mr Johnson told MPs: “What we are doing first and most directly is to ensure that those high-contact professions get expanded and targeted testing now.”

Under pressure from Labour leader Sir Keir Starmer over support for children who will not get free school meals over the summer holiday, Mr Johnson announced a £63 million support fund.

“We are announcing a further £63 million of local welfare assistance to be used by local authorities at their discretion to help the most vulnerable families,” the Prime Minister said.

“This Government has put its arms around the people of this country throughout this crisis and has done its absolute best to help.”

The Prime Minister said “we are now getting the disease under control but we will do it in a cautious and contingent way”.

He added: “We are sticking to our plan, it is a plan that is working and will continue to work.”

Sir Keir said the UK is the “outlier” compared to other countries in returning children to school, and hit out at the Prime Minister’s attack on trade unions over the problems in reopening classrooms.

“It’s no good the Prime Minister flailing around trying to blame others,” Sir Keir said.

Chancellor Rishi Sunak accepted that “every day our children are not at school is a tragedy” and told Sky News “it is obviously going to have an impact on their futures”.

The Prime Minister’s questions exchanges came after the Organisation for Economic Co-operation and Development (OECD) said Britain’s economy was likely to slump by 11.5% in 2020 – but could contract by 14% if there is a second wave of Covid-19 later this year.

The stark forecast indicated the UK’s plunge in gross domestic product (GDP) will outstrip other badly impacted European countries, in a “single-hit scenario”, with falls of 11.4% expected in France, 11.1% in Spain, 11.3% in Italy and 6.6% in Germany, while the US economy is expected to shrink by 7.3% in 2020.

Elsewhere, Health Secretary Matt Hancock refused to give a date for the full launch of the NHS contact tracing app, which had been viewed as a key part of the Government’s strategy to contain outbreaks of coronavirus as the lockdown is lifted.

“The app is progressing and we will launch it when the time is right. I am not going to put a date on it,” he said, having originally indicated it would be released in mid-May.

In other developments:

– Projections by the NHS Confederation suggested around 10 million people will be on the waiting list for NHS treatment by the end of the year – more than double the current figure.

– Mr Hancock acknowledged there would be a “very serious problem” but said he did not recognise the NHS Confederation figures.

– Zoos and safari parks are getting ready to welcome visitors after they were given the green light to open their doors from June 15 in the latest lockdown easing.

The two-metre rule poses the main barriers to firms wanting to reopen when they are given permission to do so, and Mr Johnson said it was being kept under review as the number of coronavirus cases come down.

Professor Robert Dingwall, a sociologist on one of the scientific groups advising the Government, said studies into its impact did not take account of the “economic devastation” caused by the restriction or the deaths attributable to the lockdown.

At Prime Minister’s questions, Mr Johnson said: “As we drive this disease down, as we get the incidence down, working together, I want to make sure that we keep that two metre rule under constant review.”

He said as the incidence of Covid-19 cases reduced “the statistical likelihood of being infected – no matter how close or far you are from somebody who may or may not have coronavirus – goes down”.

Mr Johnson will face further questions at the Downing Street briefing, a day before the 12-week deadline he set himself to “turn the tide” on the coronavirus outbreak.

He suggested that further information about the NHS test-and-trace programme would be published on Thursday which would demonstrate an “extraordinary degree of natural compliance” with the rules by the public.