Two Conservative MPs have urged the prime minister to abandon plans to cut Universal Credit in October.

John Stevenson and Peter Aldous have written to Boris Johnson to express their “serious concerns” over plans to remove the £20-a-week uplift to Universal Credit introduced at the start of the pandemic.

The MPs said there were “no sensible voices calling for Universal Credit to be scrapped” and called for the uplift to become permanent in order to provide people with “stability and security”.

Universal Credit should and can allow people to live with dignity and prevent people descending into spiralling situations of poor mental health, debt and destitution

They said: “This could be one of our best legacies from the pandemic and can provide the cornerstone of a social security system of which as Conservatives we can be proud.”

The pair’s letter followed analysis from the Joseph Rowntree Foundation showing around a fifth of all working-age families in the country would be affected by the cut.

In Mr Stevenson’s Carlisle constituency, 20% of working-age families will be affected, while in Mr Aldous’ Waveney constituency that figure is 26%.

In their letter, the MPs said most of those affected by the cut were already in work and now faced losing £1,040 per year from October 6.

They added: “For those unable to work, those between jobs, including those who may take a little longer to find work, and those in lower paid or insecure work – Universal Credit should and can allow people to live with dignity and prevent people descending into spiralling situations of poor mental health, debt and destitution.”

Asked about the MPs’ letter on Thursday morning, Boris Johnson told broadcasters: “The key focus for this Government is on making sure that we come out of Covid strongly, with a jobs-led recovery, and I’m very pleased to see the way the unemployment numbers, the unemployment rate has been falling, employment has been rising, but also wages have been rising. That’s the crucial thing.”

The MPs join a range of cross-party voices calling for the uplift to be made permanent, including members of Parliament’s Work and Pensions Committee and six former Work and Pensions Secretaries.

Sir Iain Duncan Smith, who introduced Universal Credit during his term as Work and Pensions Secretary, has also called for the uplift to continue.

Time is running out for the Conservatives to see sense, back struggling families and cancel their cut to Universal Credit

Labour’s frontbench has said it would “maintain the uplift” if the party were in Government, and ultimately replace UC with a “fairer” system.

Labour’s shadow Work and Pensions secretary Jonathan Reynolds MP said: “The Government’s £1,000 a year cut will be a hammer blow to millions of families, hitting the lowest paid hardest and hurting our economic recovery.

“Time is running out for the Conservatives to see sense, back struggling families and cancel their cut to Universal Credit. Labour would maintain the uplift until we can replace Universal Credit with a fairer social security system.”

A Government spokesperson said: “The temporary uplift to Universal Credit was designed to help claimants through the economic shock and financial disruption of the toughest stages of the pandemic, and it has done so.

“Universal Credit will continue to provide a vital safety net and with record vacancies available, alongside the successful vaccination rollout, it’s right that we now focus on our Plan for Jobs, helping claimants to increase their earnings by boosting their skills and getting into work, progressing in work or increasing their hours.”