Carillion said revenue in the first six months of the year had increased significantly, putting it on track to hit annual profit and earnings targets.
It said its order book and line-up of potential work stayed strong despite the expected impact of the British poll on public sector contracts.
Steady improvements in market conditions in 2014 continued in 2015 and its order book stood at about £17bn at the half-year, while potential deals totalled more than £40bn.
The group is progressing a record number of major support services contracts, including five estate deals for the UK Ministry of Defence that involve providing facilities management services for more than 70,000 properties across the UK, and a contract to supply support services to 54 prisons.
First-half revenue in Middle East construction services is expected to increase substantially compared with the first half of 2014. The group said its range of public-private partnership projects continued to do well.
The group said in a trading update: "Having entered 2015 with record revenue visibility, the group continues to be in a strong position to deal with the inevitable effects of the UK General Election on the pace of contract awards."