The company鈥檚 search for efficiency improvements, part of a bid to save 拢140m by 2013, have seen several suppliers being pressured into handing back 20% of the value of previously agreed work.
Carillion is working to reduce its list of suppliers from 25,000 companies to 5,000.
Last month Carillion signed a memorandum of understanding with the government to 鈥渞e-engineer procurement and service delivery鈥� across its support services contracts.