Hutchison Ports Australia sacked 97 workers in Sydney and Brisbane overnight on Thursday by text message and email.

When asked on Friday about the method of sacking,   Senator Abetz  said he was not aware of the circumstances.

"I don't know what the culture is in that particular workplace about communication between employee and employers – and if the culture is that employees can text message the boss and they in fact expect the boss to text message them, then that might be an appropriate methodology. I'm not going to comment on it, other than given whatever the culture might be you want employees and employers to treat each other with respect and due consideration," Mr Abetz said.

When Senator Doug Cameron asked Senator Abetz in Parliament on Monday whether he endorsed the sacking of workers by text messages, Senator Abetz said he had not condoned the method of sacking.

"The particular [Enterprise Bargaining Agreement] EBA of which we speak suggests the text messages and emails are the preferred method of communication between the boss and the workers," Senator Abetz said.

Senator Cameron then asked whether midnight text messages and emails had "replaced balaclavas and dogs as the preferred method of sacking waterfront workers". This was a reference to the 1998 waterside dispute when private security guards wearing balaclavas and accompanied by savage dogs took over Patrick Stevedores' port facilities.

Senator Abetz replied: "As I understand the sorry history of Australia's waterfront over many decades the balaclavas were in fact used by certain workers to protect themselves from being identified from retaliatory action by the MUA that has the disgraceful history of even sabotaging our World War  II effort and compromising the safety and security of Australian soldiers overseas.

"But let's be very clear: I have not condoned in any, shape or form those matters to which Senator Cameron seeks to put into my mouth," he said.

Opposition spokesman for employment, Brendan O'Connor said the ALP condemned the sacking of workers by text messages. He said Senator Abetz's comments were "heartless and demonstrative of a government that is out of touch with the challenges facing Australian workers".

Maritime Union of Australia assistant national secretary Warren Smith said the union was "shocked but not surprised" by Senator Abetz's comments. Mr Smith said the senator appeared to endorse the "thugs in balaclavas with dogs" raiding of the waterfront.

"He obviously has not got workers' interests at heart," he said.

Leyre Diaz of Maroubra is among Hutchison workers who were sacked last week.

She said she first learned of her sacking on Friday morning.

"I had the phone on silent, so I didn't see the messages about the sacking till the next morning," she said.

Joining other sacked workers at a protest in Port Botany, she said did not know how she would continue paying her weekly rent.

"I have been working here as a stevedore for a year-and-a-half and thought I had a job for life," she said.

"It's pretty scary because I'm paying $610 a week rent on my own and I have two kids and I have no family in Sydney.

"I had a housing commission place before I started here, and they told me my job here was fine."

After her six weeks holiday pay ran out, she said she faced being homeless.

"I have to pay the rent, the car bills and food for two boys 16 and 13," she said. "When I got the job, everyone was saying if you work at the wharves, it's a job for life. I thought I won the Lotto when I got the job out here."

Hutchison Ports Australia  said it was continuing to work through the redundancy process "while understanding this is a difficult time for all concerned".

"This has been a difficult decision and follows our announcement six weeks ago that the company is downsizing its service offering to the market."

The MUA and Hutchison appeared in the Fair Work Commission on Monday evening.