Health workers' union Unison says auxiliaries and health care assistants are the "most exploited" of all nursing staff.

They are paid on average £9,700 a year despite the fact that a majority said they had substituted for registered nurses some or all of the time.

Auxiliaries on locally negotiated pay awards earn even less at just £9,200 a year.

Many say they struggle to afford basic needs.

Half of the 862 nurses questioned said they had little or no supervision of their work.

There are 84,000 non-registered nursing staff in the UK.

Mature and experienced

The survey shows 60% are over 40 years old and the average length of employment as a nursing auxiliary is 12 years.

Over half of the staff, the vast majority of whom are women, would like to train as registered nurses.

However, they report that hopes of being accepted for training through doing NVQ courses are often unsuccessful.

Many say they have to fight to be allowed to do NVQs and 40% say their employers do not encourage them to take the courses.

Around a third have NVQ qualifications, but four-fifths of these said this had no effect on pay or promotion.

More than a half have seriously considered leaving the profession and more than one-fifth have a second job.

Low morale

Unison, which gives evidence before the nurses' pay review body on Wednesday, says morale is extremely low among all nurses.

Unison wants an across-the-board rise for nurses

It says an independent report shows there has been no real advance in nurses' pay trends since 1979.

Unison says nurses are falling behind similar professions, such as teaching, and is calling for a "substantial" pay rise across the board.

Unison's head of nursing Malcolm Wing said: "Our oral evidence to the review body is positive proof that nurses have been denied pay justice for a decade.

"The most exploited are nursing auxiliaries who, despite a shift in the boundaries of the profession, remain unrecognised, unrewarded and unseen. Their pay is an insult to all."

Unison's bid for more pay follows similar moves by other nursing organisations.

The Department of Health has recommended higher pay for lower grade and high grade nurses, but it wants any increases to be "fair and affordable".