The availability of candidates for job vacancies is falling, highlighting concerns about skills shortages, according to a new study.
Research by the Recruitment and Employment Confederation (Rec) and KPMG said even though unemployment remained over two million, employers were finding it difficult to fill certain jobs.
Pay rates for permanent and temporary staff had increased in recent months, the report stated.
Rec chief executive Kevin Green said: "The UK's jobs boom continues with vacancies increasing as employers look for new workers to meet increasing demand and to replace staff that have been snapped up by competitors.
"The big issue remains that employers are finding it hard to find the talent and skills they need, yet we still have 2.2 million unemployed people in the UK.
"The political debate around immigration must acknowledge this skills shortage.
"Now is the time for government to reform the visa system to ensure that the UK retains a flexible labour market so our businesses can grow and create more jobs.
"This will give young people and the long-term unemployed greater opportunities to enter the workforce and successfully progress up the career ladder."
Bernard Brown of KPMG added: " Trying to fill vacancies in the current climate must feel like wandering through a hall of mirrors for the UK's employers.
"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."
Another report, by employment firm reed.co.uk, showed that the number of apprenticeships had increased by 143% in the past year.
Most of those posted on reed's website were in business and administration, computing and telecoms, while the biggest increases over the year were in retail, construction and property.
Reed chairman James Reed said: " For the many young people completing GCSEs, A-levels and other qualifications over the coming weeks, apprenticeships offer a highly valuable and practical route to a skilled career and may be a favourable alternative to university.
"For organisations operating in sectors particularly affected by skills shortages, such as engineering, technology and manufacturing, apprenticeships are an effective route to creating a skilled, home-grown workforce."
Skills minister Matthew Hancock said: "Sharply falling unemployment brings its own challenges of skills shortages, which we are working hard to address. Radical reforms to improve education in schools are vital in the long term, and the doubling of apprenticeships over the last few years is playing a big part in tackling skills shortages.
"Employers are increasingly looking to grow their own talent through apprenticeships. A new generation of young people are seeing apprenticeships as the route to a brighter future. I want it to be the norm for school leavers to choose either university or apprenticeships."