The union said Immigration Department figures showed an increase in the granting of 457 visas for trades, despite the slowdown in the economy.

Figures showed that in the four months to October 31, 2012, the number of 457 visas granted in trades (4880) was 57% more than in the same period 12 months ago, CFMEU national construction division secretary Dave Noonan said.

“At this rate we’re looking at around 15,000 457 visas in the trades in 2012-13,” Noonan said.

The increase was 4.4 times higher than the overall increase in 457 visas.

“This increase in the use of temporary visa workers is ridiculous at a time when 68,000 jobs have been lost in construction in the last year and many skilled construction workers are looking for work,” Noonan said.

“It is clear that the current system is being misused by employers to create a pool of cheap guest workers.

“The CFMEU supports an appropriate skilled migration program but we do not support the excessive use of temporary visas when there are Australians with the necessary skills looking for work.

“There is still no obligation for employers to try and find local workers before the use 457 visa holders, so the system is ripe for abuse and too many employers are taking advantage of the system to get cheap compliant labour.”

The CFMEU yesterday launched a TV advertising campaign aimed at making the mining boom deliver jobs for Australian workers, greater investment in mining communities and better management of the economy for key sectors such as manufacturing, national secretary Michael O'Connor said.

The ads – part of the CFMEU’s “Let’s Spread it Around” campaign – tell the stories of four Australians, highlighting growing problems such as mining and construction jobs going to temporary overseas workers and manufacturing jobs disappearing due to the high Australian dollar.

Thirty-five marginal and key battleground seats are among those being targeted by the ads, with a major focus on regional Australia where the CFMEU has tens of thousands of members employed in mining, manufacturing, construction, forestry and other affected industries.

“The mining boom has created opportunities for many Australians but it has left many more behind, badly hurting job-rich sectors such as manufacturing, tourism and education,” O'Connor said.

“This campaign is about refocusing the policies of the main political parties so the big opportunities of the boom can be seized: to reduce unemployment; provide training and jobs to a new generation of Australian workers; and invest in the communities most affected.

“Now the election has been called we want to see all parties commit to better managing the mining boom and the economy for ordinary Australians.”