<p>The Construction Products Association has called on the government to invest in housebuilding and infrastructure to sustain economic growth.</p> <p>The call follows the publication of the CPA's latest state of trade survey which reveals an increase in pessimism among construction product suppliers.</p> <p>The survey comes out on the same day that the Federation of Master Builders' analysis of small and medium sized firms shows that the building industry is "in a nose dive" with one in three builders expecting workloads to fall.</p> <p>And Hometrack reports today that demand for homes is slipping and the gap between supply and demand widening prompting further price falls with signs that ongoing economic uncertainty is impacting on the market.</p>