More than a third of major government projects due to complete over the next five years are at risk of failure, according to a parliamentary watchdog.
The National Audit Office (NAO) gave red or amber-red ratings to 37 of 106 Treasury-approved schemes scheduled to finish by 2020.
This meant the projects, which range from infrastructure creation to IT overhauls, were considered either in doubt or unachievable.
Head of the National Audit Office Amyas Morse said: “I am concerned that a third of projects monitored by the authority are red or amber-red and the overall picture of progress on project performance is opaque. More effort is needed if the success rate of project delivery is to improve.”
Skills problems were identified as a major risk to successful project delivery.
“Turnover of senior responsible owners has been high,” said the NAO report. “Only four of the 73 programmes that had been in the portfolio for four years had a single senior responsible owner during that time.
“Likewise, there are still concerns around shortages of skills in specific areas such as risk management and behaviour change, which is worrying given the volume of transformation projects being undertaken.”
The government’s major projects portfolio consists of 149 projects with a combined whole-life cost of £511bn.
Civil engineers said the NAO report showed the need for the recently formed National Infrastructure Commission.
Civil Engineering Contractors Association chief executive Alasdair Reisner said: “We have long argued that the development of infrastructure in the UK has historically lacked long-term strategy.
“The NAO highlights more than ever the important role the newly established National Infrastructure Commission will play in ensuring infrastructure demand is met in an efficient manner.
“It is therefore imperative that the new commission is given real authority to assess and make proposals for long-term major infrastructure projects alongside its development of innovative solutions to fund these infrastructure requirements.”