The Institute of Public Administration's national president, Andrew Podger, said a lack of central control over recruitment and industrial relations had allowed ''classification creep'' to spiral out of control.

''We have an extraordinary number of deputy secretaries in some of our departments,'' the former departmental head and public service commissioner said yesterday.

''And it's not just that we're overpaying them and it's costing a lot of money.

''We crowd out the work for people down the line.

''You won't develop people if you don't give them responsibilities.''

The senior executive service grew by almost 40 per cent in the 14 years to 2008, rising from 1857 permanent officers to 2692.

But while most agencies managed with one to three deputy secretaries SES band-3 officers 12 agencies employed at least five.

The relatively small Department of Foreign Affairs and Trade employed 15 band-3 executives last year, most on salaries well over $200,000.

Treasury, which had only 973 permanent staff, had nine executives at deputy secretary-level, while the Australian Taxation Office, with a staff almost 25 times larger, employed just one.

A government discussion paper on the public service, issued two months ago, also identified the decentralisation of pay policy as a possible barrier to bureaucrats' mobility and development.

The paper, written by an advisory group headed by Department of the Prime Minister and Cabinet head Terry Moran, says the lack of a bureaucracy-wide pay classification system has caused ''growing disparity in remuneration levels across the APS''.

Mr Podger, who addressed a group of senior executives hosted by legal firm Deacons yesterday, warned far fewer graduates would enter the job market in 10 years time.

He said the public service needed to try harder to attract and keep the best workers.

''If you push all of the work up to the senior levels, you really are undermining professional development.

''Why are we doing it? ... Ministers and their staff like to have all those senior people. It doesn't actually help, but they think it does.

''We've got to work out a way to resist some of that.

''So let's go back to what is actually cost-effective and sensible for now and into the future.''

Public submissions to Mr Moran's public service review close on Monday next week.