The Vehicle and Operator Services Agency (VOSA) has warned that over 10 million vehicles used in the UK's roads wouldn't be fit to pass the MOT test, putting the lives of motorists and other road users at risk.
Figures released by the government body show that 40.1% of cars and vans now fail their test - equivalent to 10.4 million vehicles across the country.
This compares with the 2005 figure, when 33.5% of vehicles were unable to pass the annual MOT.
VOSA, which regulates MOT testing, also warned that 800,000 vehicles have faults that would classify them as "dangerous to drive".
The figures suggest that cash-strapped motorists are struggling to carry out regular servicing and maintenance at a time when soaringcar insurance costs and fuel prices are already adding to their financial worries.
Bill Duffy, CEO of Halfords Autocentres, said: "This data demonstrates that car-owners are sacrificing regular servicing and maintenance to help balance stretched finances. Instead they are waiting for the MOT to find out what needs fixing, but by then many cars are unroadworthy."
Meanwhile, an analysis of garage repair data has shown a 250% rise in the number of cars running on illegal tyres.
The figures come ahead of the Government's decision on a review, which could see the annual MOT test being scrapped.
Copyright © Press Association 2011