Business leaders are calling on the Government to end delays on infrastructure projects amid fears of a "lack of political will" to get schemes off the ground.
The CBI business body said there had been "too few signs of action" over the past two years and urged politicians to commit to projects that are crucial to boosting exports, unlocking business investment and supporting the overall economic recovery.
A survey of 526 businesses by the CBI and accountancy giant KPMG found a lack of confidence in government infrastructure policy that has so far failed to translate into delivery.
Two out of three firms - 65% - said they believed that government policies will have no tangible impact, or could have even a negative effect.
Only a third of businesses - 35% - said they will make a difference on the ground.
John Cridland, director-general of the CBI, said: "Government has talked the talk on infrastructure for the last two years with too few signs of action.
"The faltering speed of delivery on infrastructure creates a worrying sense that politicians lack the political will to tackle some of the major issues head-on."
He added the Coalition must commit to detailed delivery on a number of projects in the next 18 months, while starting the debate on longer-term issues such as road reforms and Britain's airport capacity.
Businesses are increasingly worried about the UK's creaking road network, with nearly half of all firms polled unhappy with domestic transport, up from 28% in 2011.
Energy costs are another major headache, with 95% of firms concerned about gas and electricity prices and 90% worried about security of supply.
Firms are also keen for ongoing improvements in Britain's digital infrastructure, with the survey showing more than 80% of firms consider faster and more reliable fixed-line and mobile broadband as critical to their success.
Richard Threlfall, a partner at KPMG, said: "Our businesses are competing each day, every day in the global market, and we need to be investing now in building great infrastructure that is a help not a hindrance to our entrepreneurial efforts.
"We know what good looks like - we need to get on and build it."
A government spokesman said: "At the Spending Round we set out £100 billion of what the report highlights as 'bold ambitions and flagship projects which if delivered will provide a significant boost to UK competitiveness'.
"The Government's focus is now on implementing these plans."