Federal Labor is using the first weekend of phased-in cuts to Sunday penalty rates to again pressure the Government to protect workers' pay.
Earlier this year, the Fair Work Commission ruled Sunday penalty rates should be cut, bringing them into line with Saturday rates for workers in the retail and hospitality sector.
Those cuts are to be phased in over three years, with the first adjustments starting this weekend.
Labor's employment spokesman Brendan O'Connor claimed up to 700,000 workers would be affected, and called on the Coalition to back Labor's bill to reinstate Sunday penalty rates.
He denied Labor's bill undermined the independence of the Fair Work Commission, opening it up to being overruled on any decision the government of its day did not agree with.
"The Parliament has already made precedence in intervening in independent umpires, and it's not unusual for parliaments to, for example, legislate having not supported an outcome in a judicial decision," he said.
Earlier, Opposition Leader Bill Shorten pledged to pass the legislation to reverse the cuts within the first 100 days of a Labor government.
Mr O'Connor argued Malcolm Turnbull had form on the matter, passing legislation to abolish the Road Safety Remuneration Tribunal (RSRT) after it faced fierce criticism of a pay order that some owner-operated businesses said would force them off the road.
"In this Parliament, over the last few years, there has already been a set precedent to intervene in decisions of independent umpires when it comes to industrial relations matters. That was set by the Prime Minister," he said.
Labor was opposed to abolishing the RSRT.
Employment Minister Michaelia Cash said that tribunal was set up merely as a political ploy, and was a different proposition to a Fair Work Commission decision.
Senator Cash said Mr Shorten's policy would harm small businesses, who benefit from the FWC decision to "level the playing field" with larger businesses who can more afford penalty rates.
"Bill Shorten has today shown that if he is ever elected to govern this country, he will be the worst enemy that small business could ever ask for," Senator Cash said.
"Small business, the biggest employer in Australia, employ millions and millions of Australia who'll basically have no future under a Labor government."
The Australian Council of Trade Unions (ACTU) claimed the Fair Work Commission's ruling was out of touch with community expectations.
"The rules are broken, and the rules have to change when those rules allow for low-paid people in this country to be forced to take a pay cut. That's the last thing that they need," ACTU President Ged Kearney said.
She urged businesses not to pass on the rate cut.
