Southwell left Atkins last September after the company stunned the industry and its own investors by warning that it was about to post an interim loss of £5m and make 400 members of staff redundant. He is now chief executive at European aerospace consortium AirTanker.
Despite Southwell's lack of a background in construction and support services prior to joining Atkins, City sourced said a consortium has approached him about launching a bid for Amey in June.
Amey is in even worse straits than Atkins; it has posted a full-year pre-tax loss of £129.5m.
A City source said that there was a heavyweight consortium behind the deal: "This is a serious group of people. If the deal was right, Southwell could be chief executive."
Former Amey chief executive Brian Staples left the group earlier this year. He is understood to be doing advisory work for venture capitalists.
Southwell declined to comment, but is believed to be mulling over the offer as he has only been in his job for a short time. A June date could, however, be too late for Amey shareholders. Several have demanded that the company be sold by the middle of next month.
The shareholders believe that this will allow a sale to reach financial close by the end of June – the deadline for Amey to buy back its £60m equity stake in the London Underground PPP. If the new owner is able to exercise this option, shareholders believe they will receive more money for their shares.
One said: "I have spoken to Amey and impressed upon it my option of a mid-May sale." Another added: "We all want to maximise value. If the buyer were also interested in the PPP, the sale would have to be finalised by the end of May."
Two weeks ago, current Amey chief executive Mel Ewell told Building that the management team wanted to sound out the views of stakeholders. He said: "We will be having detailed discussions with our major shareholders over the next two to three weeks."
City sources believe that a potential buyer would not want to rush the acquisition of a company with as many difficulties as Amey. One said: "Any buyer would want to look at the underlying business – the Tube might be a contract too far."
The company's leading shareholder, Sterling Investment Group, declined to comment, as did Amey itself.
This week, Sterling raised its stake in Amey from slightly more than 16% to 19.87%.