MPs have been warned that people from disadvantaged backgrounds may suffer if the government pushes ahead with plans to digitise the benefits system.
Over 70 organisations representing councils, charities, trades unions, business groups and housing organisations have raised concerns about the move, which will see benefit claimants access the flagship universal credit system online, according to the BBC.
They argue that millions who have never used the internet or have poor IT skills will be adversely effected by the push to ensure claims are made over the internet.
Some have also raised concerns that the computer systems required might not be sufficiently robust or ready in time for the launch.
The organisations have submitted more than 500 pages of written evidence to the House of Commons Work and Pensions Committee, which has been seen by BBC Radio 4's The World This Weekend.
A testimony from community charity Citizens Advice says: "The new universal credit system risks causing difficulties to the 8.5 million people who have never used the internet and a further 14.5 million who have virtually no ICT skills." It also raises fears that paying universal credit monthly and to just one person per household could "upset the family dynamic".
The submissions also show that many organisations support the reforms, which are being rolled out in October 2013 and will see the current five work-based benefits consolidated with just one universal credit.
In its own submission to MPs, the Department for Work and Pensions says rigorous testing of the computer system is already under way. It adds that managing universal credit online saves money and that most jobs now require computer skills. Those who struggle to use the online system will have access to face-to-face help and telephone assistance, ministers have said.
Christian Guy, managing director at the Centre for Social Justice think tank, said: "Britain's welfare system is broken and the need for radical reform could not be clearer. The current system acts as one of the biggest barriers into work and has left millions of people wasting their talents on the benefits scrapheap.
"The launch of Universal Credit will ensure that work pays and that people in employment keep more of their money. It will drive right to the heart of decades of welfare failure. A number of pilots will be run in the coming months to work through precisely some of the legitimate implementation points raised - we have all the evidence we need to get this right. The process and partnership of planning effective delivery is well advanced."