Amid claims that Australia's 457 visas for skilled workers is being abused by employers, the Australian Sex Workers' Association (ASWA) is calling on the federal government to allow the entry of foreign sex trade workers using that visa category.

In justifying their request, Jules Kim, migration programme manager of the ASWA, also known as the Scarlett Alliance, pointed out that prostitutes are also skilled workers who should be granted four-year work visas.

She said that at present the Immigration Department finds sex work not a skilled occupation which explains why escorts are not covered by the 457 visa.

"That's discriminatory and we want equal rights," Ms Kim was quoted by Courier Mail.

In its submission to the Senate, the alliance stressed that the skills of prostitutes involves "working with condoms and dams, negotiating prices and services, performing STI (sexually transmitted infection) checks, making risk assessments and establishing boundaries."

However, Immigration insisted providing sexual services is not considered a skill because it does not require a degree or diploma nor is it recognised as a trade qualification.

But Scarlett said it could provide training through a Diploma in Community Education.

Ms Kim warned that overseas sex trade workers would be likely victims of trafficking and exploitation if they could not be granted long-term work visa, while foreign backpackers could not work in brothels if they are above 30 years old and are from China, Africa or Pacific Island nations.

In response to the push by Australian unions to scale back the grant of 457 visas because employers use it to undercut wages of Aussie workers and exploit foreigners, the federal government introduced legislation to force employers to advertise jobs in Australia first and prove they tried but failed to hire a local before they would be allowed to bring in someone with a 457 visa.

The latest report said that the number of Temporary Business 457 visas went up 20 per cent in the past 12 months to 108,810.

Justifying the rise in 457 visas, Immigration Minister Brendan O'connor said, "Genuine skill shortages do exist in industries and locations right across Australia and we are attempting to ensure they get filled, while at the same time making sure locally skilled people don't miss out on work."

The department recently removed five occupations under the categories of retail pharmacy and aircraft engineering in the Skilled Occupation List.