PwC revealed it remained in negotiations with a buyer for all four main trading businesses nearly eight weeks after the insolvency team were called in.
If a deal cannot be agreed the firm’s £2m worth of plant will be sold off once a creditors meeting has been held on 1 July at the Heathrow Marriott.
Together the contracts, plant hire, waste and soil stabilisation firms owe £11.5m to trade contractors and suppliers.
PwC has retained just over half of the group’s 155 staff to complete two major contracts on the M25 and Heathrow Terminal 2 which were assessed to be profitable when McArdle collapsed on 22 April.
The M25 job is expected to complete next month with work at Heathrow expected to complete in August.
The £60m turnover firm has been in business for more than 40 years after expanding from its original haulage roots.
McArdle ran into cashflow problems due to the underperformance of the waste division and a general disconnect between finance and operations, according to PwC.
The firm owes £4m to its bank and £107,000 to staff, which is likely to be paid in full if the main Colnbrook headquarters in Berkshire are sold.
Trade creditors of the J McArdle Contracting business could recover a fraction of the £5.3m they are owed.