Nearly 70 per cent of Australians believe the minimum wage is too low, including a strong majority of Coalition voters, a new poll has found.

Only one in five Australians believe the $17.70 an hour minimum wage is "about right" and just four per cent of people think it is too high, according to the polling commissioned by the peak union body, the ACTU.

Conducted last week, the Essential Research online poll of 1015 people found 69 per cent of Australians want a higher minimum wage, with 33 per cent of those respondents saying it should be "much higher". Nearly 60 per cent of Liberal National voters believe it should be higher, as do 77 per cent of Labor voters.

The ACTU has asked the workplace relations umpire to raise the minimum wage by $45 a week, triple the 2016 $15.80 increase. Such an increase would lift the minimum wage to $37,420 a year.