The Work and Pensions Secretary told MPs the temporary uplift, introduced to help protect people during the coronavirus pandemic, would start to be “phased out” from late September.
Therese Coffey insisted a commitment had been “honoured” as charities warned that it made “no sense” and would damage the mental health of people living in poverty.
She said: “A collective decision was made within government to make sure the £20 uplift was extended for six months, and that is being honoured.
“But a collective decision was made that as we see the economy open up, we shift the focus strongly onto getting people into work and jobs.
“So it’s not in any way assuming everything’s going to be OK, but it is why… we’ve doubled the number of work coaches, the different programmes we’ve invested in, or are investing in, and we’re also not putting our head in the sand.
“We’ve just started the restart programme which is the long-term unemployed programme. We’re forecasting it’ll last for three years, expecting a million people to take advantage of that."
Just days ago six former Conservative work and pension secretaries urged the Chancellor to make the uplift permanent, warning that failing to do so would “damage living standards, health and opportunities” .
Jonathan Reynolds MP, Labour’s Shadow Secretary of State for Work and Pensions criticised the decision.
He said: “The Government’s plans to cut Universal Credit will hit the lowest paid hardest and hurt our economic recovery.
"Six million families are set to lose £1000 a year while out of work support will be left at its lowest level in decades.
“There is near universal opposition to this cut, including from prominent Conservatives. It is time the Government saw sense, backed struggling families and cancelled their cut to Universal Credit.”
Shadow Secretary of State for Scotland, Ian Murray MP added:“There is near universal opposition to this shameful and callous cut to Universal Credit.
“By the government’s own reckoning, there could be hundreds of thousands or even millions of people self-isolating in September because of Boris Johnson’s Covid strategy, yet the Tories see fit to slash support for those in need.
“Reducing Universal Credit will hit the most vulnerable people in our society hardest. It’s time the Tories see sense, back struggling families and reverse this cut.”
The SNP Work and Pensions spokesperson David Linden MP urged Boris Johnson to reconsider or face “monumental consequences”.
He said: “Despite numerous reports from leading anti-poverty organisations like the Joseph Rowntree Foundation and the Trussell Trust, who have urged the UK government to make the uplift permanent and extend to legacy benefits, we are yet to see any progress.
“We know that by making the uplift permanent, we could prevent as many as 700,000 people – of which 300,000 are children and 60,000 live in Scotland – from being plunged into poverty, yet these cruel cuts remain on the table.”
The Treasury insisted this week it was “right” that financial support was wound down as measures are eased.