If you are one of almost half a million Australians working in the nation's hotels, restaurants, cafes, bars and shops, you just lost out again.

Late last night a Labor bid to stop cuts to penalty rates going ahead was defeated, but not before Federal Government backbencher George Christensen crossed the floor to vote with the Opposition.

Now hundreds of thousands of workers, including some of the country's lowest paid, are facing a significant wage cut.

Who loses out?

If you're a full or part-time retail, fast food, restaurant, hospitality or pharmacy worker and you're not part of an enterprise bargaining agreement with your employer, you will lose out, as will most casual staff.

While penalty rates will still apply, they will be significantly reduced.

For full and part-time workers for example, Sunday hospitality pay rates will be cut from 175 per cent of their standard wage to 150 per cent. Public holiday rates will fall from 250 per cent to 225 per cent.

In retail, Sunday wages will fall from 200 per cent of the standard rate to 150 per cent. On public holidays the penalty rate will fall from 250 per cent to 225 per cent.

If you work night shifts you will also face pay cuts.

For example, the 10 per cent evening work penalty for fast-food workers will apply from 10.00pm to midnight, instead of from 9:00pm.

The 15 per cent after midnight penalty will apply to hours worked between midnight and 6.00am, instead of 7:00am.

What about the dollar figures?

The Australian Council of Trade Unions (ACTU) has said that nearly half a million people will lose up to $6,000 a year.

The amount you will lose depends on your rate of pay and the number of hours you work on Sundays and public holidays.

And don't forget the $22 per week minimum wage increase which comes into effect from July 1.

When will the cuts take effect?

The public holiday penalty cuts will come into effect at the start of next month.

The Sunday rate cuts will take effect from the same date, but the Fair Work Commission says it will phase these in over three or four years so workers may not feel the pinch for some time.