It could also lead to building some five million square feet of business and commercial space. Marshall Aerospace and Defence Group (MADG) say they have put forward the Cambridge Airport site for development. A company spokesman said: "We have always maintained that we will only consider these moves when we are confident that our businesses will be stronger as a result of any move, and that Cambridge will benefit from the development of the site. "We believe that both of these criteria can now be met, hence these linked announcements." The spokesman added: "Whilst there is a great deal of work still to be done before any final decisions can be made we have identified three preferred locations which could be viable sites for Marshall Aerospace and Defence Group. "In alphabetical order, these are: Cranfield, Duxford and Wyton." The company says its hopes to complete a move to a new site by 2030. Alex Dorrian, executive chairman of Marshall said: "This is a momentous day for Marshall, when two opportunities coincide to create a launch pad for ambitious longterm plans for the future of Marshall and also for Cambridge. " Our commitment to our businesses, our employees, and to Cambridge is driven directly by our shareholders. "This is the beginning of an exciting phase for Marshall, during which time we will build on our success and focus ever more closely on delivering a unique Marshall experience to our customers. "There is a great deal of ground to be covered before any decisions can be announced and that work is now underway." Marshall of Cambridge was founded in 1909 and now comprises three principal businesses: Marshall Aerospace and Defence Group; Marshall Group Properties; and Marshall Ventures which holds the Group's 65 per cent majority shareholding in Marshall Motor Holdings plc, as well as Marshall Fleet Solutions and the company's investment arms, Martlet and MarQuity. The combined group has annual sales in excess of £2.5bn and 6,000 employees.