Almost a quarter of WA apprentices and trainees are walking away from their training, sparking fears young workers in unskilled mine jobs will be left without work as the boom slows.
Department of Training and Workforce Development figures show 10,816 traineeships and apprenticeships were cancelled in the year to June.
That was up from 8208 cancellations in 2009-10.
The number of people completing apprenticeships in the same period fell from 6287 to 4897.
WA Group Training Scheme chief executive Frank Allen said low pay was a key factor.
"Who would want to come in on $400-500 a week as an apprentice, having to buy tools, when you could go to the mines and pick up $100,000 a year," he said.
"The mining industry should contribute in times like these. They take all the skilled tradesmen to build mine sites and should inject something back into society and train the younger generations."
Mr Allen said construction trades were hardest hit, with about 50 apprentices quitting this year.
"We're not going to have any tradesmen left if the Federal Government doesn't open its mind and look for a solution," he said.
WA Training Minister Murray Cowper said the cancellations should not be taken in isolation.
"A cancellation of an apprenticeship can be the result of a wide range of factors, including commencing an alternative apprenticeship or finding other employment," he said. "With the second highest rate of completions in the nation, we not only offer quality courses but some of the best employment opportunities in the country."
Chamber of Commerce and Industry WA chief executive James Pearson said businesses were cutting spending.
"Uncertainty will put pressure on businesses considering the long-term investment of up to four years to train an apprentice or trainee," he said. "Over the same period, we have seen an increase in the take-up of apprentices and trainees and this may level out the numbers not completing their training."
But UnionsWA president Meredith Hammat said the standard of training had fallen in WA.
Apprentices were poorly paid so it was no wonder many dropped out for higher-paid, low-skill jobs.
"We're seeing a real dumbing down of our technical and trade skills and that is not good for the long term," she said.