Talks will continue later to try to save the troubled construction firm Carillion amid reports it could collapse by Monday.
The future of the government contractor is being discussed at high-level Whitehall meetings, the BBC understands.
Carillion has debts of £1.5bn, including a £587m pension shortfall.
It is involved in major projects such as the HS2 high-speed rail line, as well as managing schools and prisons.
The firm is trying to reach an agreement with creditors, but sources have said the firm has a “matter of days” as it teeters on the edge of collapse.
The consultancy EY has been put on notice in case the company falls into administration.
On Friday, reports that creditors had rejected a potential rescue plan sent Carillion’s shares down by more than 28%.
- HS2 Building part of the high-speed rail line between London, Birmingham, Leeds and Manchester
MoD homes Maintains 50,000 homes for the Ministry of Defence
Schools Manages nearly 900 buildings nationwide
Network Rail Second largest supplier of maintenance services
Prisons Holds £200m in prison contracts
“But it is a going concern… and hopefully they’ll be able to work with their partners to get the working capital they need to continue providing important services,” he told the Andrew Marr Show.
Mr Lewis refused to be drawn on whether the government would bail the company out.
“It’s a very commercially sensitive situation so I wouldn’t comment further than to say I would hope to see that the working capital that they need will be there working with their partners,” he said.
Liberal Democrat leader Sir Vince Cable has urged the government not to agree to a taxpayer-funded bailout.
Alastair Stewart, a construction and property analyst at Stockdale Securities, said none of the solutions involving the government were “particularly palatable”.
“There’s a number of ways in which the government can get involved but politically none of them are particularly palatable,” said.
Share price plummeted
It specialises in construction, as well as facilities management and ongoing maintenance.
Since then, its share price has plummeted and it is now worth just £61m.
In December, it convinced lenders to give it more time to repay them.
However, the company’s banks, which include Santander UK, HSBC and Barclays, are understood to be reluctant to lend it any more cash.
Its problems stem in part from a string of risky contracts which have proved unprofitable.
It also faced payment delays in the Middle East that hit its accounts.
It has worked on high-profile projects, including the Battersea Power station redevelopment and the Anfield Stadium expansion.
However, it is also the second largest supplier of maintenance services to Network Rail and maintains 50,000 homes for the Ministry of Defence, manages nearly 900 schools and manages roads and prisons.
The concern is that if it were to collapse these key public sector services could suffer a lot of disruption.