Work on revamping Queen Elizabeth Hospital in Kings Lynn has been delayed.
Work costing over £1bn will now start between 2027 and 2028, health secretary Wes Streeting said.
It had been due to be finished by 2030 though hospital staff say this is not likely.
It was one of a number of hospital schemes proposed under the previous Conservative government.
Labour minister Streeting claims the delay is due to no way of funding the projects having been allocated until now.
Alice Webster, CEO at The QEH, said: “The revised plan will allow us to move forward with confidence and focus, ensuring we continue to progress at pace.
“We remain committed to delivering a new hospital for our local community. The timescales in this plan indicate our new hospital will not meet the previous deadline of 2030 – we have been nationally assured that work is under way to prioritise bringing these timescales forward where possible.
“As a Reinforced Autoclaved Aerated Concrete (RAAC) hospital the safety of our current building remains our priority and our failsafing programme is progressing well. Yesterday’s announcement outlines the need for site-by-site survey report commissioned by the Government on each RAAC hospital – we await more information on this work.”