Mace has upped its tender prices forecast for 2015 as contractors increasingly seek to boost margins and walk away from bidding risky jobs.

The cost consultancy arm of the contractor said construction was becoming a sellers’ market amid rising demand.

Mace has hiked its tender prices forecast for the year by 1%, both nationally to 4.5% and in London to 5.5%.

Rival cost consultants EC Harris and Gleeds are going even further predicting tender prices will rise by 7.5% and 7.0% in the capital this year.

The hardening line being taken by main contractors with clients is causing some tension.

One major private residential client told the Enquirer: “We are looking seriously at changing our favoured contractors because our existing firms are trying to push up prices too far.”