The research, compiled with KPMG and Markit, looks at hiring trends across 400 UK recruitment consultancies.
Four in ten (40%) said there were fewer available permanent candidates than there had been in the previous month, with only 8% reporting there were more.
For temporary staff, 32.6% said there were fewer candidates to pick from, while only 9.8% said availability had improved.
Despite the continued fall in the number of available candidates, the amount of people placed into roles has also risen every month this year. For permanent staff, 43% of employers reported an increase in the number of new hires, compared to just 18% whose recruited fewer.
The figures are similar for temporary workers, where 39% of employers increased their hiring activity, with just 17% placing fewer temporary staff.
Employers are becoming increasingly frustrated by a lack of available talent, said Bernard Brown, partner and head of business services at KPMG.
“Trying to fill vacancies in the current climate must feel like wandering through a hall of mirrors for the UK’s employers," he said.
"No sooner are they in a position to reflect the improving economy by creating roles and offering tempting salaries, than the search for talent seems to reach a dead end, with candidates either preferring to hide in the shadows or failing to offer the appropriate skills."
Melanie Forbes, managing director of recruitment outsourcing specialists Guidant Group, told HR magazine employers will increasingly need to become more proactive to find the skills they need.
"Attracting the passive candidates, those who are not looking for work, is increasingly important," she said. "To do this, companies who may have scaled back their HR teams during the recession may have to shift back into development mode quickly."