The firm is refusing to get involved in suicide bidding which has seen a string of rivals go bust during the last twelve months.

Results for the year to December 31 2012 show pre-tax profits fell to £1.2m from £4.9m last time as turnover ticked-up to £193.8m from £183.8m.

Chairman Russell Race said: “We expect our markets to experience fierce competition for available workload and continuing margin pressure.”

Group chief executive Mark Lawrence added: “We have continued to see local and national competitors exit the market, usually as a result of sustained unrealistic bidding.

“We have made it clear previously that our group businesses will not bid for work at negative margins, and at times we have chosen to exit a tender process that would have resulted in a commercially unsustainable bid.”

TClarke is a regular winner of prestige contracts in the London market and its order book currently stands at a record £230m compared to £190m last year.

Lawrence said: “In the capital we continue to secure some of the most significant schemes that have come to market and whilst price remains the most influential factor, financial strength, reputation and quality of people plays an equally important part.

“When a client decides on a project award, it is these secondary factors that differentiate T Clarke from its competitors.”

TClarke’s North and Scotland operations are also profitable and the firm is expanding its presence in the FM, residential and transport markets alongside its core M&E operations.