Worried staff at collapsed construction firm Carillion have been warned not to speak to media and to keep their concerns and questions private, a leaked internal memo reveals.

Bosses issued the directive to the firm’s 20,000 UK staff just minutes after news of the company’s collapse was reported on Monday.

“Do not speak to the media and be careful not to share any information on social media as this will be unhelpful to all of us,” the memo, obtained by HuffPost UK, states.

The document, issued to Carillion workers through internal email, advises line managers to pass information on to staff who don’t use computers.

[Work at Carillion? Speak with a HuffPost journalist in full confidence. Email George.Bowden@huffpost.com or WhatsApp +44 7896 804043]

Daniel Easthope, a regional managing director, addressed staff in the memo, saying: “I know this is an exceptionally sad day – and I know that many of you will have lots of questions about what happens next.

“We will endeavour to get you as much information as we can, as soon as we can.”

The company holds dozens of government contracts in schools, hospitals and defence sites.

The firm delivers cleaning services, facilities management and even school dinners across Britain.

But it was some of the firm’s overseas deals which led it to issue a series of profit warnings amid mounting debt of up to £2bn and a £600m pension deficit.

While the government has said it will continue to honour Carillion’s public contracts, it has left the firm’s private projects in limbo.

These include several construction projects in London and Manchester.

And ministers on Tuesday turned their attention to Carillion’s top brass, by demanding a fast-track investigation into claims of mismanagement.

HuffPost has approached Carillion for comment.

[Work at Carillion? Speak with a HuffPost journalist in full confidence. Email George.Bowden@huffpost.com or WhatsApp +44 7896 804043]