The number of WA people in training and apprenticeships has dropped by 1700 in a year - the biggest fall in five years - prompting fears of a skills crisis.
New figures showed 41,000 people in WA were in training or in an apprenticeship in December last year, which was a 4 per cent drop on 12 months previously.
The total number of people starting a new course or apprenticeship was down 12.7 per cent in the same period.
UnionsWA boss Meredith Hammat blamed the $40 million budget cuts to the TAFE sector in 2014-15 for undermining the quality of training, which influenced the take-up and dropout rates.
"This is not a plan to address youth unemployment or provide skills needed for our future," she said.
"Despite WA's rapidly growing population, we now have fewer skilled workers for housing construction, car repair and maintenance."
WA Group Training Scheme chief executive Frank Allen said both the demand and the supply of apprentices was steadily reducing.
He blamed a government- imposed pay rise for apprentices for undermining demand for them from employers, claiming tradesmen now preferred to use cheaper trowel hands.
Mr Allen said supply was down partly because the Federal Government had slashed subsidies for providers by more than a third in three years.
"We are in a crisis because we are facing a massive skills shortage," Mr Allen said.
Acting Minister for Training and Workforce Development John Day said the numbers in training had moderated in line with the economic conditions.
He said data released by the National Centre for Vocational Education Research showed apprentice and trainee figures were down across the country.
"WA experienced a 4 per cent decline compared with 12.9 per cent for Australia overall," he said.