The Regatta Quay development, which includes a 20-storey building known locally as the 'wine rack', was taken over by administrators in 2010.
The Irish government owns the site after buying Irish bank debts.
The administrators said completing the ??100m buildings was dependent on the property market.
Work on Regatta Quay started in 2007, but it stopped as City Living Developments (Ipswich) Ltd, which had borrowed from the Anglo Irish and Allied Irish banks, went into administration.
Ben Gummer, Conservative MP for Ipswich, said it was "almost a metaphor" for the British economy.
"It's property speculation gone mad and a banking system which is bust, so it's going to take a lot of time to put that right," he said.
"The administrators are actively trying to find a developer to take on the work, so things are moving now but I'd like to see them move quicker."
Baker Tilly were appointed administrators for Regatta Quay by Ireland's National Asset Management Agency.
The accountancy firm is also the administrator for The Mill development next to Regatta Quay.
Regatta Quay has 118 flats built, with space for 150 more in the 'wine rack'. The Mill has 194 completed and 140 uncompleted flats.
Nigel Millar, from Baker Tilly, said: "It's very difficult to say when building work could resume.
"We'll certainly be in administration for two years. How long we'll be in administration depends on how sales progress."
Savills, which is the estate agent for the sites, said sale prices for a two-bedroom apartment had dropped from about ??300,000 in 2008 to ??175,000.
Andy Redman, from Savills, said: "If we can continue to sell at the rates we're achieving of 3-4 flats a month, then it may bring things forward, but it's dictated by market conditions."
Administrators say work will not resume on an unfinished block of flats on Ipswich waterfront until 96 completed apartments are sold.