If shareholders reject the rescue plan, the board has warned that lenders would instantly place the group into a pre-pack administration, leaving shareholders with nothing.

The firm said the new delisted firm would continue to trade saving many of the firm’s 39,000 UK jobs and pensions. It is also understood that a shadow board has been lined up as a contingency.

But there have been no assurances for trade contractors and suppliers. They face seeing sums they are owed wiped out.

One specialist contractor told the Enquirer: “Generally payments have been flowing. But we are bracing for the worst.

“There is real concern about the fallout across Interserve’s supply chain, many also work for Kier.”

Interserve must secure the support of 50% of voting shareholders.

Largest shareholder, Coltrane Asset management, which holds a near 28% stake in the debt-ridden group, has said it will vote against proposals to swap £485m of Interserve’s £631m debt in return for most of its equity.

Existing shareholders would be left with just 5% of the shares.

Coltrane has also threatened to hold Interserve bosses personally liable for millions of pounds of losses should the firm fall into administration.

The ballot will be held today at 11am.